5. Calculate the equilibrium point given the following algebraic expression of demand and supply. a. If the equation for a market demand curve is Qa= 100- 0,5P and the equation for a market supply curve is Qs = -20 + P, the market equilibrium price and quantity are: (10) b. If the equation for the demand curve is Q = 45-2P and the equation for the supply curve is Q = -21 +4P, then the equilibrium values for price and quantity are: (10) 6. What is the difference between change in demand and change in quantity demanded? (4), Use example on one of these expressions (1).