Posted by Erin on .
The profit p(x) of a cosmetics company , in thousands of dollars . is given by p(x) =5t^2=400x2550, where x is the amount spent on advertising in thousands of dollars
a) determine the maximum profit the company can make
b) dtermine the amount spent on advertising that will result in the maximum profit
c) what amount must be spent on advertising to obtain a profit of at least $ 4 000 000

Math( help please ! ) 
Reiny,
Your equation makes no sense, make sure you read what you typed before posting.

Math( help please ! ) 
Sharlene,
a. Complete the square.
5x^2 + 400x  2550
= 5(x^2  80x)  2550
= 5(x^2  80x + 1600  1600)  2550
= 5(x + 40)^2 + 8000  2550
= 5(x + 40)^2 + 5450
5450 x 1000 = $5,450,000
b. x = 40
40 x 1000 = $40000
c. Between $22 971 & 57 029