I just need help with letter C please

Question

A manufacture has been selling 1950 television sets a week at $450 each. A market survey indicates that for each $11 rebate offered to a buyer, the number of sets sold will increase by 110 per week.a) Find the demand function , where  is the number of the television sets sold per week. −10​+645Correct  b) How large rebate should the company offer to a buyer, in order to maximize its revenue?$127.5Correct  

c) If the weekly cost function is , how should it set the size of the rebate to maximize its profit?$  

Answer 1

p(x) = (1950 + 110x)(450 - 11x)