estion-01: Given the national income model, E = C+ / + G, where C=100+ 0.75Y, I =120-20r, G =80, T = 0.5Y (that is t = 0.5) a) Derive an expression for equilibrium in the goods market (Y = E) in the form g ()). b) Find the equilibrium National Income and expenditure. c) If MPC decreases to 0.6, how will: i. The expenditure equation change? ii. The equilibrium level of income change? d) Confirm your answer graphically by plotting on the same diagram the Y a equations before and after MPC decrease