The marginal price for a weekly demand of x bottles of shampoo in a drugstore is given by the function shown below. Find the price-demand equation if the weekly demand is 150 when the price of a bottle of shampoo is $2. What is the weekly demand when the price is $7.50? p' (x) = -9,000 (3x+ 50)2 Find the price-demand equation. (Type an equation.)