Question

Greg is opening a car wash. He estimates his cost equation as C = 9000 + 0.09x and his revenue equation as R = 1.85x, where x is the number of cars washed in a six-month period. Find the number of cars that must be washed in a six-month period for Greg to make a profit.

Answer 1

9000+0.09x = 1.85x

subtract 0.09x from each side

9000 = 1.76x

divide both sides by 1.76

x = 9000/1.76

x = 5113. 64

 he needs to wash 5114 cars to make a profit.