7. When a wholesaler sold a product at $35 per unit, sales were 500 units per week. After a price drop of $5 per unit, the sales increased to 520 units per week. Assume that the relationship between the price p and the units sold per week x is linear Find the demand function p in terms of x. (16 points) a) Find the revenue function R(x). b) How many units must be produced to maximize the revenue? c) Find the maximum revenue. d) 6