The supply and demand for crabmeat in a local fish store are related by the equations:

Demand p=D(q)=19-2q and

Supply p= S(q)=6q+3

When p represents the price in dollars per pound and q represents the quantity of crabmeat in pounds per day.

a.) Find the quantity supplied and demanded at each of the following prices: $10, $15, $18.

b.) Find the equilibrium point.