7. (2.5 pts each) Find the cost function for each marginal cost function. a. C'(x) = 3x - 7; fixed cost is $9 0.01x b. C'(x) = 0.5e ; fixed cost is $15 8. (2.5 pts each) Find the demand function for each marginal revenue function. (hint, if no items are sold revenue is $0) 2 1. R'(q) = 17.5 -0.2q - 0.3q 2. R'(q) = 425 - 0.3q