3. 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. D(x) = 1800(x + 1) 2, S(x) = 2(x +1)2 a. Find the equilibrium point. b. the consumer surplus at the equilibrium point. c. the producer surplus at the equilibrium point