Question: Demand and supply curves can also be represented with equations. Suppose that the quantity demanded, QD, is represented by the following equation: QD = 90 - 2P
The quantity supplied, QS, is represented by the equation: QS = P
a. Find the equilibrium price and quantity.
b. Suppose that the price is $20. Determine QD and QS.
c. At a price of $20, is there a surplus or a shortage in the market?
d. Given your answer in part c, will the price rise or fall in order to fi nd the equilibrium point?