3. [10 pts] Consider the following demand function d(x) and supply function s(x). d(x) = 700 -0.6x s(x) = 0.8x a) Find the market demand (equilibrium point the positive x value where demand and supply are equal). b) Find the consumers' surplus at the market demand found in part (a). c) Find the producers' surplus at the market demand found in part (a).