Question 800982
C(d) cost of rental per day

C(d) = 85 +0.5x

for 3 days 3(85+0.50x)

3(85+0.50x)=375

/3
85+0.50x=125

0.50x=125-85

0.50x=40

x= 40/0.50

x= 80 miles