Bus Econ 13.1.50 Question Help Find the demand function for the marginal revenue function. Recall that if no items are sold, the revenue is 0. R'(x) = 0.09x - 0.05x + 146 p(x) =Bus Econ 13.1.51 Question Help Find the cost function if the marginal cost function is given by C'(x) = x 2/3 + 3 and 27 units cost $243. C(x) =