2-7 solving equations with rational numbers learn to solve equations with rational numbers
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2-7 Solving Equations with Rational Numbers
Learn to solve equations with rational numbers.
2-7 Solving Equations with Rational Numbers
m + 4.6 = 9
m + 4.6 = 9Use the Subtraction Property of Equality. Subtract 4.6 from both sides.
Once you have solved an equation it is a good idea to check your answer. To check your answer, substitute your answer for the variable in the original equation.
Remember!
Additional Examples 1A: Solving Equations with Decimals
Solve.
4.4 m =– 4.6 = – 4.6
2-7 Solving Equations with Rational Numbers
8.2p = –32.8
–4p =
Use the Division Property of Equality. Divide both sides by 8.2
–32.8 8.2
8.2p 8.2
=
Additional Examples 1B: Solving Equations with Decimals
Solve.
2-7 Solving Equations with Rational Numbers
Additional Examples 1C: Solving Equations with Decimals
x = 18
Use the Multiplication Property of Equality. Multiply both sides by 1.2
= 15x 1.2
x 1.2
= 1.2 • 15 1.2 •
Solve.
2-7 Solving Equations with Rational Numbers
m + 9.1 = 3
m + 9.1 = 3Use the Subtraction Property of Equality. Subtract 9.1 from both sides.
Check It Out: Example 1A & 1B
–6.1 m =
–9.1 = –9.1
Solve.A.
B. 5.5b = 75.9
75.9 5.5
5.5 5.5 =b
13.8b =
Use the Division Property of Equality. Divide both sides by 5.5
2-7 Solving Equations with Rational Numbers
= 90
Check It Out: Example 1C
y = 405
Use the Multiplication Property of Equality. Multiply both sides by 4.5
y 4.5
y 4.5
= 4.5 • 904.5 •
Solve.
C.
2-7 Solving Equations with Rational Numbers
2 7
= –3 7
n +
Additional Example 2A: Solving Equations with Fractions
n – + = – –2 7
3 7
27
27
n = – 5 7
Subtract from both sides.2 7
Solve.
2-7 Solving Equations with Rational Numbers
1 6 = 2
3y –
Additional Example 2B: Solving Equations with Fractions
Find a common denominator; 6.
y = 5 6
=y 4 6
1 6
+
1 6
= 2 3
–1 6
+ 1 6
+y Add to both sides.1 6
Solve.
Simplify.
2-7 Solving Equations with Rational Numbers
5 6
= 5 8
x
Simplify.
Additional Example 2C: Solving Equations with Fractions
Divide both sides by .5 6
Solve.
2-7 Solving Equations with Rational Numbers
1 9
= – 5 9
n +
Check It Out: Example 2A
n – + = – –1 9
5 9
19
19
n = – 2 3
Subtract from both sides.1 9
Simplify – .6 9
Solve.
2-7 Solving Equations with Rational Numbers
1 2 = 3
4y –
Check It Out: Example 2B
Find a common denominator; 4.
y = 1 1 4
=y 3 4
2 4
+
1 2
= 3 4
–1 2
+ 1 2
+y Add to both sides.1 2
Solve.
Simplify.
2-7 Solving Equations with Rational Numbers
Simplify.
Check It Out: Example 2C
Divide both sides by .3 8
x =16 19
3 8
= 6 19
x
Solve.
2-7 Solving Equations with Rational Numbers
Standard Lesson Quiz
Lesson Quizzes
Lesson Quiz for Student Response Systems
2-7 Solving Equations with Rational Numbers
Lesson Quiz: Part I
Solve.
1. x – 23.3 = 17.8
2. j + = –14
3. 9y =
4.
115
y =
x = 41.1
3 5
2 3
3 4
j = –155 12
d4 = 2 3
812
d = 9
2-7 Solving Equations with Rational Numbers
Tamara can mow acre in one hour. If her yard is 2 acres, how many hours will it take her to mow the entire yard?
Lesson Quiz: Part II
5.
5 hours
2 5
2-7 Solving Equations with Rational Numbers
1. Solve.
a – 36 = 44.9
A. a = 36.7
B. a = 49.2
C. a = 59.9
D. a = 80.9
Lesson Quiz for Student Response Systems
2-7 Solving Equations with Rational Numbers
2. Solve.
c + = –11
A. c = 12 C. c = 11
B. c = –12 D. c = 11
Lesson Quiz for Student Response Systems
11
2011
20
4 5
3 4
3 4
4 5
2-7 Solving Equations with Rational Numbers
3. Solve.
8e =
A. e = 8 C. e =
B. e = 5 D. e =
Lesson Quiz for Student Response Systems
2 3
1 3
1 12
3 20
2 3
2-7 Solving Equations with Rational Numbers
4. Solve.
= 3
A. h = 9 C. h = 11
B. h = 10 D. h = 12
Lesson Quiz for Student Response Systems
1 2
1 2
1 2
1 2
h 3
5 6