Question

The demand and supply functions of a goods are given by:
p=-4QD+120
p=1/2QS+28
where P, QD, and QS denote the price, quantity demanded and quantity supplied respectively. Find the equilibrium price and quantity.

Answer 1

$$QD=30-\dfrac{1}{4}p$$

$$QS=2p-56$$

In equilibrium Qd = Qs

$$30-\dfrac{1}{4}P=2p-56$$

$$\dfrac{9}{4}P=86$$

$$P=38.22$$

$$Qd=Qs=22$$