Best Rentals charges a daily fee plus a mileage fee for renting its cars. Barney was charged $111.00 for 3 days and 300 miles, while Mary was charged $198.00 for 5 days and 600 miles. What does Best Rentals charge per day and per mile?

Answer 1

Eq1: 3x + 300y = 111
Eq2: 5x + 600y = 198
Multiply Eq1 by -5 and Eq2 by 3 :
-15x - 1500y = -555
+15x + 1800y = +594
Sum: 300y = 39
Y = $0.13 per mile.

In Eq1, replace Y with 0.13 and solve for X:
3x + 300*0.13 = 111
3x = 111 - 39 = 72
X = $24 per day.