Alright, let's do this! If $25 is one fifth of how much the game system cost then, multiply 25 times 5. And you should get your answer. I hope this helps.
The interval that f(x) is increasing is the distance from 200 to 300. The minimum value of f(x) in the interval 0<x<300 is 200. At a value of 500, the value of f(x) is 0. The function can't be a quadratic function since there are two points in the graph where f(x) changes its rate from increasing to decreasing or the opposite. A quadratic function has only one of that point.
