7 In economics revenue R is defined as the amount of money received from the sale of a product and is equal to the unit selling price p of the product times the number x of units actually sold That is R xp The Law of Demand states that p and x are related As one increases the other decreases Suppose that p and x are related by the following demand equation A Express the revenue R as a function of p x 4p 100 0 p 25 B What is the revenue if 18 units are sold c Sketch the graph of the revenue function D What quantity x maximizes revenue what is the maximum revenue 700 600 500 400 Revenue dollars 300 200 100 4 8 Price dollars 12 16 20 24