Consider the fictitious good Derp. The demand for Derp is Q=1200-2P. Suppose the supply of Derp is given by Q=-600 +2P.
What is the equilibrium price of Derp?
What is the equilibrium quantity of Derp?
What is the price elasticity of demand at the equilibrium price and quantity?
What is the price elasticity of supply at the equilibrium price and quantity?