May I please get some help

Let R(x), C(x), and P(x) be, respectively, the revenue, cost, and profit, in dollars, from the production and sale of x items. If R(x) = 4x and C(x) =0.001x + 1.8x + 40, find each of the following. a) P(x) b) R(50), C(50), and P(50) c) R'(x). C'(x), and P'(x) d) R'(50), C'(50), and P'(50) a) P(x) = N (Use integer's or decimals for any numbers in the expression.)