Demand: Qd=90-4P, where Qd is quantity demanded and P is
price
Supply: Qs=-100+15P, where Qs is quantity supplied and P is
price
Recall that equilibrium price was 19, while quantity was 50. At
that price, the price elasticity of demand was -0.80.
Now I want you to rearrange each equation, putting P on the
left-hand side, and solve again for equilibrium P and Q (you ought
to get the same answer).
Now we want to figure the monopoly price. Take...