Question

The cost to rent a car is $25 plus an additional $0.15 for each mile the car is driven. How many miles was a car driven if it had a bill of $71.80?479645454312Please explain the answer.

Answer 1

Since the form of the linear equation is

$y=mx+b$

m is the rate of change

b is the initial amount

Since the cost of the rental car is $25 and $0.15 for each mile, then

The initial amount is 25 dollars

b = 25

The rate of change is 0.15 dollars per mile

m = 0.15

Then the equation is

$T.C=0.15x+25$

T.C is the total cost

x is the number of miles

Since the given total cost is $71.80

Then T.C = 71.8

$71.8=0.15x+25$

Subtract 25 from both sides

$\begin{gathered} 71.8-25=0.15x+25-25 \\ \\ 46.8=0.15x \end{gathered}$

Divide both sides by 0.15

$\begin{gathered} \frac{46.8}{0.15}=\frac{0.15x}{0.15} \\ \\ 312=x \end{gathered}$

The car was driven for 312 miles

The answer is the last option