7th Grade Math

Chapter Study Guide and Review 419

Multi-Part Lesson Review

Rates and Functions

Equations and Functions (Lesson 1B)

Copy and complete each function table.

Then identify the domain and range.

13. y = 2 x x 2 xy
    12 × 12
    22 × 2
    32 × 3
    4
    5


14. y = 11 x x 11 xy
    0 11 × 00
    1 11 × 1
    2
    3
    4
    5

EXAMPLE 1 Curtis can drive his car 28

miles for every gallon of gasoline. Make a

function table to show how many miles

he can drive on 1, 2, 3, and 4 gallons. Then

identify the domain and range.

Input Function Rule Output

Gallons of

Gasoline

Multiply

by 28

Total

Miles

1 28 × 1 28

2 28 × 2 56

3 28 × 3 84

4 28 × 4 112

The domain is {1, 2, 3, 4} and the range is

{28, 56, 84, 112}.

Functions and Graphs (Lesson 1C)

Graph the function represented by the table.

15. Texting
    Time (min) Total Words
    0 0
    1 20
    2 40
    3 60

Graph each equation.

16. y = 4 x - 2 17. y = x + 6


17. RUNNING Damon runs the 100-meter dash
    at an average speed of 8 meters per
    second. The equation d = 8 t describes
    the distance d that Damon can run in
    t seconds at this speed. Represent the
    function by a graph.

EXAMPLE 2 Graph y = 3 x + 2.

Select any four values x 3 x + 2(x, y)

0 3(0) + 2 (0, 2)

1 3(1) + 2 (1, 5)

2 3(2) + 2 (2, 8)

3 3(3) + 2 (3, 11)

for the input x. We

chose 0, 1, 2, and 3.

Substitute these

values for x to find

the output y.

Graph the ordered pairs. y

0 x

1

2

3

4

5

6

7

9

10

11

8

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Lesson 1

418_422_C07_SGR_895130.indd 419 12/31/09 4:35 PM