Question

Instead of driving a car, Corey rides a bike to work. Corey paid $408 for the bike. He also pays an average of two dollars per week for upkeep on the bike. Corey knows that he can recover these costs over time because he'll be saving money on gasoline. Corey's car used nine gallons of gas per week going to and from work. If gas costs four dollars per gallon, how long will it take Corey to recover the costs associated with his bike?

Answer 1

bike costs y=2x+408 4*9=36 car weekly cost y=36x
2x+408=36x
-34x+408=0
-34x=-408
-34x/-34=-408/-34
x=12
Answer, 12 Weeks