Three difffrent questions to be answer

The short-run behaviour of an economy is described by the its IS curves Y=21-3r. and the monetary policy (MP) curve: r=2+0.6TL. where it is inflation, r is the real interest rate, Y is real GDP. Then, the aggregate demand curve of this economy can be written in form Y=a-bit. Calculate parameter a.Suppose that the IS curve of an economy can be written as Y=38-5r. The monetary policy (MP) curve is: r=4+1TL. Finally, the equation of the aggregate supply curve: IT= TI +1.3(Y-14) Suppose that the economy is a in a long-run equilibrium when an oil price shock shifts up the short-run AS curve by 4 units. Calculate output in the new short-run equilibrium.In an economy the consumption function has the forms C(V-T. 1)=12+07(Y-T)-50. The investment function is Kr =49-5r. In both cases the unit of the real interests rate is a percentage point. The real GDP is100, the government purchase is 28 while net taxes are 19, Calculate the equilibrium interest rate in percentage points