Question

Gabriela is washing cars. She charges $15 for a car wash. She paid $145 for advertising, and uses $3 worth of cleaning products on each car she washes. When will Gabriela begin to make a profit? (a) Write an inequality to model the problem. (b) Solve t

Answer 1

I found that she starts to make a profit after the `12^(th)` car.

Explanation:

We can translate the situation into an algebraic expression where `x` is the number of washed cars, as:
`x(15-3)-145>0` to find when she starts to make a profit:
So:
`12x-145>0`
`12x>145`
`x>145/12=12.08~~12` after the `12^(th)` car she starts to make a profit:
if `x=13`:
`13*12-145=$11`