Help me with Calculus

Question

In a certain chemical manufacturing process, the daily weight y of defective chemical output depends on the total weight x of all output according to the empirical formula

y=0.04x+0.0005x^2

where x and y are in pounds. If the profit is $300 per pound of non-defective chemical produced and the loss is $60 per pound of defective chemical produced, how many pounds of chemical should be produced daily to maximize the total daily profit?

Answer 1

P = 300x - 60(x/25 + x^2/2000)

x = 4960