5. Consider the economic functions for Benin, a small country in West Africa:

Desired consumption Cd = 1400 + 0.5(Y - T) - 200r.

Desired investment I d = 900 - 200r.

Real money demand L = 0.5Y - 200i.

Full-employment output Y = 4600 trillion CFA franc, the currency of Benin.

Expected inflation pe = 0.

a. Suppose that T = G = 920 and that M = 9000.

Find an equation describing the IS curve. (Hint: Set desired national saving and desired investment equal, and solve for the relationship between r and Y.) Find an equation describing the LM curve.

(Hint: Set real money supply and real money demand equal, and again solve for the relationship between r and Y, given P.) Finally, find an equation for the aggregate demand curve. (Hint: Use the IS and LM equations to find a relationship between Y and P.) What are the general equilibrium values of output, consumption, investment, the real interest rate, and price level?

b. Suppose that T = G = 920 and that M = 4500.

What is the equation for the aggregate demand curve now? What are the general equilibrium values of output, consumption, investment, the real interest rate, and price level? Assume that fullemployment output Y is fixed.

c. Repeat part

(b) for T = G = 800 and M = 9000.