6th Grade Math Textbook, Fundamentals

362 Chapter 13

13-6

%:#AR

Company

$30 fee

plus

$10 per hour

Graph Linear Functions

Objective To graph a linear function • To identify ordered pairs of a linear function from

its graph •To use a graphing calculator to graph linear functions

The EZCar Company charges $10 per hour plus a $30
fee to rent a car. You can show the relationship between
the number of hours a car is rented and the total cost of
renting the car by using a function, a function table,
and a graph.

To write the function, first define the variables.

Then write a function expressing the relationship

between the two variables.

Let xthe number of hours a car is rented.

Let ythe total cost of renting a car.

Total cost Hours rented Fee

y  10 x  30

Cost per hour

Use the function to make a function table. Choose at least two input values.

Then substitute the values into the function to find the corresponding output values.

Use the input and output values from the function table

to write a list of ordered pairs. Then plot and connect the points.

Notice that all the points lie on a straight line.

The line represents allthe ordered pairs of the function y  10 x 30.

x y ^10 x^30 y

0 10(0)  30 30

2 10(2)  30 50

4 10(4)  30 70

6 10(6)  30 90

8 10(8)  30 110

0

y

x

21 36745 8 910

10

20

30

40

50

60

70

80

100

90

110

120

y  10 x  30

(x, y)

(0, 30)

(2, 50)

(4, 70)

(6, 90)

(8, 110)