Suppose an imaginary economy is represented by the following equations_GDP= C + IC= $100 + 0.8 Y DI = I Planned + I UnplannedIplanned = $200AEplanned = C+IPlanned(1)Calculate the income- expenditure equilibrium level GDP. Show your work.(2)Suppose the level of planned investment spending (Iplanned) drops by $50 . What will the new equilibrium GDP be? Show your work(3)With Iplanned back at the original level $200, suppose that autonomous consumption spending decreases from $100 to $60. What will the new equilibrium be? Show your work.(4)Calculate the value of the multiplier.