Hello, first time poster! I'm currently stuck on this polynomial word problem and really need some help. Before I start showing what I tried heres a link to a picture of the problem. https://imgur.com/a/7WvOd

Part a) of the problem is asking for a profit of $0 or too just break even. Seems simple (i think). I first set the equation to 0.

0 = -5x^2 + 550x - 5000

I solved the problem and got..

0 = -5(x-10)(x-100)

So the zeros are x = 10 and x =100, does that mean the company has to spend between 10,000 - 100,000 dollars to break even?

Part b) If I got 'a' right, to find "How much should be spent on advertising to achieve a maximum profit?" I should do 10 + 100 / 2 which gives me 55 (mid point). Since the question is in thousands of dollars to would cost 50,000 dollars in advertising to achieve a maximum profit?

Part c) Do I replace x in the equation to 55? Like, P(55) = -5(55)^2 + 550(55) - 5000 = 10,125. So the maximum profit is 10,125 dollars or do I have to multiply 10,125 by 1000 also to get 10,125,000?

part d) need help with this..

I'm not sure if I did any of this correctly, if someone could please help me out that would be amazing!