Assume that C(x) is in dollars and x is the number of units produced and sold. For the total-cost function C(x) = 0.01x +0.5x + 50, find AC and C'(x) when x = 80 and Ax = 1. AC = $ (Simplify your answer. Type an integer or decimal rounded to two decimal places as needed.) C'(x) when x = 80 is $ (Type an integer or a decimal.) per unit.