Part A:
Full size car rental is $49/day, insurance is $21/day, and the total is $465 after a coupon for $25. Ok. We have to add the daily charges, then multiply that by the number of days. Next we’ll subtract his coupon, and get $465:
(49 + 21)d - 25 = 465
70d - 25 = 465
70d = 490
d = 7
7 days is this answer.
Part B:
Now that we did part A, this is a little easier to come up with an equation for, right? ;)
(39 + 21)d - 25 = 465
60d = 490
d = 8.16
8 days is this answer
Part C:
Now we don’t know the cost of the car, so that is x. But we know we still have to add that to the 21 for insurance, and multiply that sum by the 5 days they’re renting it. On the other side of the equation, Marven and his 3 friends spent $75 each, so our total is 75 x 4.
(x + 21)5 = 75 x 4
5x + 105 = 300
5x = 195
x = 39
They rented the smaller car.
Hope this helped. LMK if you have any questions.