10.5 Exercise 82

Solve. Round answers to the nearest tenth.

A computer store owner estimates that by charging $x$ dollars each for a certain computer, he can sell $40 - x$ computers each week. The quadratic equation $R = − x^{2} + 40 x$ is used to find the revenue, $R$, received when the selling price of a computer is $x$. Find the selling price that will give him the maximum revenue, and then find the amount of the maximum revenue.