Question

A 3-mi cab ride costs $7.30. A 8-mi cab ride costs $15.30. Find a linear equation that models a relationship between cost c and distance d.

Select one:
a. c = 1.91d + 2.50
b. d = 1.60c + 8.00
c. c = 1.60d + 2.50
d. c = 2.43d + 8.00

Answer 1

Option c)
`c=1.60d+2.5`

Explanation:

Let

d -----> the distance in miles

c ----> the cost in dollars

we have the ordered pairs

(3,7.30) and (8,15.30)

step 1

Find the slope of the linear equation

The slope is equal to

`m=(15.30-7.30)/(8-3)`

`m=(8)/(5)`

step 2

Find the equation of the line in point slope form

`c-c1=m(d-d1)`

we have

`point\ (3,7.30)`

`m=(8)/(5)`

substitute

`c-7.30=(8)/(5)(d-3)`

`c=(8)/(5)d-(24)/(5)+7.30`

`c=1.60d+2.5`