A rental car company charges $35 a day plus $.15/mi for a mid-size car. A customer owes $117.15 for a three-day rental. How many miles did the customer drive?

They drove 81 miles

Step-by-step explanation:

Total cost = fees per day * days + miles * mileage charge

We know the total cost = 117.15

We know it was 3 days at 35/day

The mileage charge is. 15 per mile

117.15 = 35*3 + m*.15

Multiplying

117.15 = 105+.15m

Subtract 105 from each side

117.15-105 = 105-105 +.15m

12.15 =.15m

Divide by. 15 on each side

12.15 /.15 =.15m/.15

81 = m

They drove 81 miles