Question

Bob and Carl each rented the same kind of moving truck from EZ Move. There was a flat rental fee plus a charge per mile that the truck was driven. Bob’s cost for his truck was $112.96 for 138 miles. Carl’s cost for his truck was $142.78 for 209 miles. Which equation can be used to represent the cost of the rental truck?

Round to the nearest hundredth if necessary.
y = 71 x minus 29.82
y = 25 x minus 66
y = 0.42 x + 71
y = 0.42 x + 55

Answer 1

Find the slope: m = (142.78 − 112.96) / (209 − 138) = 29.82 / 71 = 0.42.
Then solve for the intercept: 112.96 = 0.42(138) + b → b = 112.96 − 57.96 = 55.

So the equation is y = 0.42x + 55.