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Simplify each expression. 1. SOLUTION: 2. SOLUTION: 3. SOLUTION: 4. SOLUTION: eSolutions Manual - Powered by Cognero Page 1 10 - 2 Simplifying Radical Expressions

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Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 1

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 2

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

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10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 4

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 5

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 6

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 7

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 8

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 9

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 10

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 11

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 12

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 13

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 14

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 15

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 16

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 17

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 18

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 19

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 20

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 21

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 22

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 23

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 24

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 25

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 26

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 27

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 28

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 29

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 30

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 31

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 32

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 33

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 34

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 35

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 36

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 37

10-2 Simplifying Radical Expressions

Simplify each expression.

1. 

SOLUTION:  

2. 

SOLUTION:  

3. 

SOLUTION:  

4. 

SOLUTION:  

5. 

SOLUTION:  

6. 

SOLUTION:  

7. 

SOLUTION:  

8. 

SOLUTION:  

9. 

SOLUTION:  

10. MULTIPLE CHOICE  Which expression is equivalent to ?

A  

B  

C  

D  

SOLUTION:  

The correct choice is D.

Simplify each expression.

11. 

SOLUTION:  

12. 

SOLUTION:  

13. 

SOLUTION:  

14. 

SOLUTION:  

15. 

SOLUTION:  

16. 

SOLUTION:  

Simplify each expression.

17. 

SOLUTION:  

18. 

SOLUTION:  

19. 

SOLUTION:  

20. 

SOLUTION:  

21. 

SOLUTION:  

22. 

SOLUTION:  

23. 

SOLUTION:  

24. 

SOLUTION:  

25. 

SOLUTION:  

26. 

SOLUTION:  

27. 

SOLUTION:  

28. 

SOLUTION:  

29. 

SOLUTION:  

30. 

SOLUTION:  

31. 

SOLUTION:  

32. 

SOLUTION:  

33. 

SOLUTION:  

34. 

SOLUTION:  

35. ROLLER COASTER  Starting from a stationary position, the velocity v of a roller coaster in feet per second at

the bottom of a hill can be approximated by , where h is the height of the hill in feet.

  a.  Simplify the equation. b.  Determine the velocity of a roller coaster at the bottom of a 134-foot hill.

SOLUTION:  a.

b. To determine the velocity of the roller coaster at the bottom of the hill, substitute 134 for h in the equation

.

The roller coaster will have a velocity of about 92.6 ft/sec at the bottom of a 134-foot hill.

36. CCSS PRECISION  When fighting a fire, the velocity v of water being pumped into the air is modeled by the

function , where h represents the maximum height of the water and g represents the acceleration due to

gravity (32 ft/s2).

a.  Solve the function for h. b.  The Hollowville Fire Department needs a pump that will propel water 80 feet into the air. Will a pump advertised to project water with a velocity of 70 feet per second meet their needs? Explain. c.  The Jackson Fire Department must purchase a pump that will propel water 90 feet into the air. Will a pump that is advertised to project water with a velocity of 77 feet per second meet the fire department’s need? Explain.

SOLUTION:  a.

b. To determine the height of the water, substitute 70 for v in the function .

A pump with a velocity of 70 feet per second will pump water only to a maximum height of 76.6 feet. Therefore, thispump will not meet the fire department’s need.

c. To determine the height of the water, substitute 77 for v in the function .

A pump with a velocity of 77 feet per second will pump water to a maximum height of 92.6 feet. Therefore, this pump will meet the fire department’s need.

Simplify each expression.

37. 

SOLUTION:  

38. 

SOLUTION:  

39. 

SOLUTION:  

40. 

SOLUTION:  

41. 

SOLUTION:  

42. 

SOLUTION:  

43. 

SOLUTION:  

44. 

SOLUTION:  

45. 

SOLUTION:  

46. 

SOLUTION:  

47. 

SOLUTION:  

48. 

SOLUTION:  

49. ELECTRICITY  The amount of current in amperes I that an appliance uses can be calculated using the formula

, where P is the power in watts and R is the resistance in ohms.

a.  Simplify the formula. b.  How much current does an appliance use if the power used is 75 watts and the resistance is 5 ohms?

SOLUTION:  a.

b. Substitute P = 75 and R = 5 in the equation .

An appliance uses about 3.9 amps of current if the power used is 75 watts and the resistance is 5 ohms.

50. KINETIC ENERGY  The speed v of a ball can be determined by the equation , where k is the kinetic

energy and m is the mass of the ball. a.  Simplify the formula if the mass of the ball is 3 kilograms. b.  If the ball is traveling 7 meters per second, what is the kinetic energy of the ball in Joules?

SOLUTION:  a. If the mass of the ball is 3 kilograms, substitute m = 3 into the equation.

b. Substitute V = 7 in the equation .

The kinetic energy of the ball is 73.5 Joules.

51. SUBMARINES  The greatest distance d in miles that the lookout can see on a clear day is modeled by the formula

. Determine how high the submarine would have to raise its periscope to see a ship, if the submarine is the

given distances away from a ship.  

SOLUTION:  First solve the equation for h.

 

Distance 3 6 9 12 15

Height = d2

h = (3)2 = 6

h = (6)

2 = 24

h = (9)

2 = 54

h = (12)

2 = 96

h = (15)

2 = 150

52. CCSS STRUCTURE  Explain how to solve .

SOLUTION:  To solve an equation of equal ratios, first find the equal cross products and then solve for the variable. 

 

Use the conjugate of     to rationalize the denominator.  

 

So, the solution is .

53. CHALLENGE Simplify each expression. 

a.

 

b.

 

c.

   

SOLUTION:  

a.

 

b.

 

c.

54. REASONING  Marge takes a number, subtracts 4, multiplies by 4, takes the square root, and takes the reciprocal to

get . What number did she start with? Write a formula to describe the process.

SOLUTION:  Let x = a number.

55. OPEN ENDED  Write two binomials of the form  and  . Then find their product.

SOLUTION:  

Two binomials of the form  and  are  and  .

56. CHALLENGE  Use the Quotient Property of Square Roots to derive the Quadratic Formula by solving the

quadratic equation ax2 + bx + c = 0. (Hint: Begin by completing the square.)

SOLUTION:  

57. WRITING IN MATH  Summarize how to write a radical expression in simplest form.

SOLUTION:  No radicals can appear in the denominator of a fraction. So, rationalize the denominator to get rid of the radicand in the denominator. Then check if any of the radicands have perfect square factors other than 1. If so, simplify. For example, simplify the following.

58. Jerry’s electric bill is $23 less than his natural gas bill. The two bills are a total of $109. Which of the following equations can be used to find the amount of his natural gas bill? A  g + g = 109 B  23 + 2g = 109 C  g − 23 = 109 D  2g − 23 = 109

SOLUTION:  Let g = Jerry’s natural gas bill. Jerry’s electric bill is $23 less than his natural gas bill, so the electric bill is g – 23.The two bills are a total of $109.

So, the correct choice is D.

59. Solve a2 − 2a + 1 = 25.

F  −4, −6 G  4, −6 H  −4, 6 J  4, 6

SOLUTION:  Solve for a.

The roots are –4 and 6. So, the correct choice is H.

60. The expression  is equivalent to which of the following?

A  

B  

C  

D  

SOLUTION:  

So, the correct choice is C.

61. GRIDDED RESPONSE  Miki earns $10 an hour and 10% commission on sales. If Miki worked 38 hours and had a total sales of $1275 last week, how much did she make?

SOLUTION:  Miki’s earnings are $10 per hour and 10% commission on sales.

Miki made $507.50 last week.

Graph each function. Compare to the parent graph. State the domain and range.

62. 

SOLUTION:  

The parent function   is multiplied by a value greater than 1 and is subtracted by the value 1, so the graph is

a vertical stretch of followed by a translation 1 unit down. The domain is {x|x ≥ 0}, and the range is {y |y  ≥ -1}.

x 0 1 2 3 4 y –1 1 ≈ 1.8 ≈ 2.5 3

63. 

SOLUTION:  

The parent function is multiplied by a value less than 1 and greater than 0, so the the graph is a vertical

compression of . Another way to identify the compression is to notice that the y-values in the table are

times the corresponding y-values for the parent function. The domain is {x|x ≥ 0} and the range is {y |y  ≥ 0}.

x 0 1 2 3 4 y 0 ≈ 0.7 ≈0 .9 1

64. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of y = followed by a translation 2 units left. The domainis {x|x ≥ –2}, and the range is {y |y  ≥ 0}.

x –2 –1 0 1 2 y 0 2 ≈ 2.8 ≈ 3.5 4

65. 

SOLUTION:  

This graph is the result of a reflection across the x-axis of the graph of followed by a translation 1 unit left.

The domain is {x|x ≥ –1}, and the range is {y |y  ≤ 0}.

x –1 0 1 2 y 0 –1 ≈ –

1.4 ≈ –1.7

66. 

SOLUTION:  

This graph is the result of a vertical stretch of the graph of followed by a reflection across the x-axis, and

then a translation 3 units right. The domain is {x|x ≥ 3}, and the range is {y |y  ≤ 0}.

x 3 4 5 6 y 0 –3 ≈ –

4.2 ≈ –5.2

67. 

SOLUTION:  

The parent function   is multiplied by a value less than 1 and is added to the value 1, so the graph is a vertical

stretch of followed by a reflection across the x-axis, and then a translation 1 unit up. The domain is {x|x ≥ 0}, and the range is {y |y  ≤ 1}.

x 0 1 2 3 y 1 –1 ≈ –

1.8 ≈ –2.5

Determine the domain and range for each function.

68. f (x) = |2x − 5|

SOLUTION:  Since f (x) cannot be negative, the minimum point of the graph is where f (x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.    

x 0 1 2 3 4 f (x) 5 3 1 1 3

69. h(x) = |x − 1|

SOLUTION:  Since h(x) cannot be negative, the minimum point of the graph is where h(x) = 0. 

  Make a table of values.

 

  The domain is all real numbers, and the range is {y | y ≥ 0}.  

x –4 –2 0 2 4 h(x) 5 3 1 1 3

70. 

SOLUTION:  This is a piecewise-defined function. Make a table of values. Be sure to include the domain values for which the function changes.  

  Notice that both functions are linear.

  The domain is all real numbers, and the range is {y | y ≤ 1}.

x -1 0 1 2 3 g(x) -2 -1 0 1 -5

Solve each equation by using the Quadratic Formula. Round to the nearest tenth if necessary.

71. x2 − 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = –25.

The solutions are 5 and –5.

72. r2 + 25 = 0

SOLUTION:  For this equation, a = 1, b = 0, and c = 25.

There are no real positive square roots of –100. Therefore, the solution to this equation is ø.

73. 4w2 + 100 = 40w

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 4, b = –40, and c = 100.

The solution is 5.

74. 2r2 + r − 14 = 0

SOLUTION:  For this equation, a = 2, b = 1, and c = –14.

The solutions are –2.9 and 2.4.

75. 5v2 − 7v = 1

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 5, b = –7, and c = –1.

The solutions are −0.1 and 1.5.

76. 11z2 − z = 3

SOLUTION:  Rewrite the equation in standard form.

For this equation, a = 11, b = –1, and c = –3.

The solutions are −0.5 and 0.6.

Factor each polynomial, if possible. If the polynomial cannot be factored, write prime .

77. n2 − 81

SOLUTION:  

78. 4 − 9a2

SOLUTION:  

79. 2x5 − 98x

3

SOLUTION:  

80. 32x4 − 2y

4

SOLUTION:  

81. 4t2 − 27

SOLUTION:  

In this trinomial, a = 4, b = 0 and c = –27, so m + p is zero and mp is negative. Therefore, m and p must be opposite signs. List the factors of 4(–27) or –108 with a sum of 0.

There are no factors of –108 with a sum of 0, so 4t2 − 27 is prime.

Factors of –108 Sum of 0 1, –108 –107 –1, 108 107 2, –52 –50 –2, 52 50 3, –36 –33 –3, 36 33 4, –27 –23 –4, 27 23 6, –18 –12 –6, 18 12 9, –12 –3 –9, 12 3

82. x3 − 3x2 − 9x + 27

SOLUTION:  

83. POPULATION  The country of Latvia has been experiencing a 1.1% annual decrease in population. In 2009, its population was 2,261,294. If the trend continues, predict Latvia’s population in 2019.

SOLUTION:  Use the equation for exponential decay, with a = 2,261,294, r = 0.011, and t =10.

Latvia’s population in 2019 will be about 2,024,510 people.

84. TOMATOES There are more than 10,000 varieties of tomatoes. One seed company produces seed packages for 200 varieties of tomatoes. For how many varieties do they not provide seeds?

SOLUTION:  Let t be the number of varieties of tomatoes for which the seed company does not produce. Since the seed companyproduces packages for 200 varieties, the total number of varieties can be expressed as: t + 200.    Since there are more than 10,000 varieties of tomatoes: t + 200 > 10,000.   Solving, we get:  t > 10,000 - 200 t > 9,800

Write the prime factorization of each number.85. 24

SOLUTION:  

86. 88

SOLUTION:  

87. 180

SOLUTION:  

88. 31

SOLUTION:  The number 31 is prime. So, the prime factorization of 31 is 31.

89. 60

SOLUTION:  

90. 90

SOLUTION:  

 

eSolutions Manual - Powered by Cognero Page 38

10-2 Simplifying Radical Expressions