7) the weekly revenue for a product is given by R(x)=138.6x-0.015x^2 and the weekly cost is C(x)=10,000 + 69.3x^2+0.00001x^3 , where x is the number of units produced and sold.

a. how many units will give the maximum profit? (round to the nearest whole number as needed)

b. What is the maximum possible profit?