Suppose that the demand curve for a particular commodity is Qd = a- bP and the supply curve for this commodity is Qs = c+dP. The parameters a,b,c and d are positive constants.
a. Find the equilibrium price and quantity as a function of the constants a,b,c and d.
b. Impose a tax of $u per unit on this good. Show that the total amount paid by consumers will be the same regardless of whether the tax is imposed on producers or consumers.