John has a job parking cars. he earns a fixed weekly salary of $300 plus a fee of $5 for each car he parks. at what point does john begin to earn more from fees than his fixed salary? justify your answer.

Let us assume the number of cars parked after which John will start earning more than his fixed weekly salary = x
The fixed weekly salary of John = $300
The fee that John gets for parking each car = $5
Then we can get the equation as
5x = 300
x = 300/5
   = 60
So from the above deduction we can see that John will earn the equal amount of his weekly pay after he parks 60 cars. Then it becomes obvious that parking car number 61, John will start earning more than what he gets as his fixed weekly salary. I hope you have understood the described method.