let d is the number of days of rental car
At Trinity's Tire World, $50 a day plus $75 fee: 50*d + 75
At India's Auto, $35 a day plus $105 fee: 35*d + 105
To find out after how many days, they both cost the same
50*d + 75 = 35*d + 105
50d + 35d = 105 - 75
15d = 30
d = 30/15
d = 2
Answer: after 2 days, they both cost the same amount of money
Proof:
50*d + 75 = 50*2 + 75 = 100 + 75 = 175
35*d + 105 = 35*2 + 105 = 70 + 105 = 175
Hope that helps
