Given the following algebraic expressions for supply and demand, supply: Q=5+2P Demand: Q= 9-2P a) calculate the equilibrium price and quantity by solving the two equations for price and quantity. b) For the equations defined in part(a), show that when you substitute the equilibrium price into either the supply or demand equations, you get the same equilibrium quantity. c) suppose that the demand curve shifts as a result of an increase in consumers' incomes. The new demand equation is Q=13-2P. Calculate the new equilibrium price and quantity