The total-cost, C(x), and total-revenue, R(x), functions for producing x items are shown below, where 0 S x $ 800. C(X) = 5800 + 400x and R(X) - - 2 5X + 800x (a) Find the total-profit function P(x). (b) Find the number of items, x, for which the total profit is a maximum. ... .. (a) P(x) = 5X"+400x - 5800 (Simplify your answer.) (b) The profit is maximized for a production of units. (Simplify your answer.)