SOLUTION: You and your friend each start a car-washing service. You spend $25 on supplies and charge $10 per car. Your friend spends $55 on supplies and charges $13 per car. How many cars do

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: You and your friend each start a car-washing service. You spend $25 on supplies and charge $10 per car. Your friend spends $55 on supplies and charges $13 per car. How many cars do      Log On


   

Question 957184: You and your friend each start a car-washing service. You spend $25 on supplies and charge $10 per car. Your friend spends $55 on supplies and charges $13 per car. How many cars do you have to wash to earn the same amount of money as your friend?
Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
Let x be the number of cars. We will find out how many cars you have to wash to make as much money as your friend:
10x - 25= 13x - 55 Add 25 on both sides and subtract 13x, also both sides:
-3x = -30 Now divide both sides by -3:
x= 10 cars you have to wash.
Check: 10(10)-25=13(10)-55; 100-25=130-55; 75=75 Correct.