WRITE LINEAR EQUATIONS IN SLOPE-INTERCEPT FORM

December 2, 2013

Pages 283-285

y-interceptANSWER

slopeANSWER

Copy and complete the statement.

?In the equation y = mx + b, the value of m is theof the graph of the equation.

1.

?In the equation y = mx + b, the value of b is theof the graph of the equation.

2.

parallelANSWER

3.

?Two lines are if their slopes are equal.

Find the slope of the line that passes through the points.

ANSWER 3 4

4. (4, 5), (2, 3) ANSWER 1

5. (0, – 6), (8, 0)

6. (0, 0), (– 1, 2) ANSWER – 2

Identify the slope and the y-intercept of the line with the equation.

7. y = x + 1

8. y = x – 6 3 4

3 4

, –6ANSWER

1, 1ANSWER

9. y = – 25

x– 2 25

,– 2ANSWER –

Evaluate the function when x = – 2, 0, and 4.

10. f(x) = x – 10

11. f(x) = 2x + 4

12. f(x) = – 5x – 7

0, 4, 12ANSWER

3, – 7, – 27ANSWER

– 12, – 10, – 6ANSWER

13. Write an equation of the line with a slope of – 2 and a y -intercept of 5.

y = mx + b Write slope-intercept form.

y = – 2x + 5 Substitute – 2 for m and = for b.

14. Which equation represents the line shown?

The line crosses the y-axis at (0, 3). So, the y-intercept is 3.

y = mx + b Write slope-intercept form.

2y = – x + 35

2Substitute – for m and 3 for b.5

= = –The slope of the line is riserun

–2 5

25

.

A y = – x + 325 B y = – x + 35

2

C y = – x + 125 D y = 3x +

25

15. Write an equation of the line shown in slope-intercept form.

y = mx + b

y = x – 543

Substitute for m and 5 for b.43

–

STEP 1

Write an equation of the line. The line crosses the y-axis at (0, – 5). So, the y-intercept is – 5.

SOLUTION

x2 – x1 33 – 0y2 – y1=m =

– 1 – (– 5)=

4

Write slope-intercept form.

Calculate the slope.

STEP 2

SOLUTION

16. Write an equation for the linear function f with the values f(0) = 5 and f(4) = 17.

Calculate the slope of the line that passes through (0, 5) and (4, 17).

Write f(0) = 5 as (0, 5) and f (4) = 17 as (4, 17).STEP 1

x2 – x1 4 – 0y2 – y1=m =

17 – 5= 4

12=3

STEP 2

y = mx + b Write slope-intercept form.

y = 3x + 5 Substitute 3 for m and 5 for b.

Write an equation of the line. The line crosses the y-axis at (0, 5). So, the y-intercept is 5.

STEP 3

ANSWER

The function is f(x) = 3x + 5.

HOMEWORKChapter 5, section 1

Pages 286-289

#4-14, even

#18-38, even

#53-54, all