D(x) is the price, in dollars per unit, that consumers are willing to pay for x units of an item, and S(x) is the price, in dollars per unit, that producers are willing to accept for x units. Find (a) the equilibrium point, (b) the consumer surplus at the equilibrium point, and (c) the producer surplus at the equilibrium point. D(x) =(x -9] , S(x)=x7+ 4x + 15 (a) What are the coordinates of the equilibrium point? (Type an ordered pair.) (b) What is the consumer surplus at the equilibrium point? (Round to the nearest cent as needed.) (c) What is the producer surplus at the equilibrium point? (Round to the nearest cent as needed.)