The demand and supply for a particular commodity are given by the following two equations: Demand: P = 75 - 2Qd and Supply: P = -15 + 4Qs where Qd and Qs are quantity demanded and quantity supplied, respectively, and P is price. Using the equilibrium condition Qs = Qd, determine equilibrium price and equilibrium quantity. Equilibrium price: $ Equilibrium quantity: units