PLEASE HELP ME

[Darlyne]

The waste hauling company profits are stated as the difference between revenue and costs. That is P(x) = R(x) – C(x), where x is the number of tons processed. Find the maximum profit and the number of tonnage which must be processed in order to yield the maximum profit for the following:
R(x) = 20x – 0.1x2; C(x) = 4x +2

 

[stapel]

So subtract the costs C from the revenues R, simplify, and then either take the derivative and maximize, or else (like you did back in algebra) find the vertex of the parabola. Either way should give you the same answer.

Eliz.