Question

A car detailing company charges $30 plus $18 per hour. Another company charges $25 plus $20 per hour. How long is a job that costs the same no matter which company is used? (There should be a variable on both sides of the equal sign/equation)

Answer 1

The startup equation for this would be 30 + 18h = 25 + 20h. Subtract 20h from both sides to get 30 - 2h = 25. Now, you should subtract 30 from both sides. When you do, you get -2h = -5. Divide each side by -2 to isolate the h. h = 2.5. A job that costs the same no matter which company is used is 2.5 (2 1/2) hours long.