How to solve these

Z =C+I+G (1) Planned aggregate expenditure C = 3.75 + [0.5 - 8] YD (2) Consumption function I =1 -s (3) Planned investment G =2 (4) Government expenditure YD =Y-T (5) Disposable income T = 1 +0.25Y -TR (6) Net Tax function Y = Z (7) Equilibrium Condition QUESTION 3 Consider the model in Question 1. Calculate Equilibrium Consumption (C*) when there is no COVID-19 and no transfers (l.e. s-0 and TR-0) QUESTION 4 Consider the model in Question 1, calculate the government's budget deficit when there is no COVID-19 and no transfers (i.e. s=0 and TR-0) QUESTION 5 Consider the model in Question 1. Calculate the equilibrium value of the government multiplier if the economy is affected by COVID.19 with a- 0.20 but there are no transfers (TR=0) QUESTION 6 Consider the model in Question 1. Calculate the equilibrium output (1) if the economy is affected by COVID-19 with s-0.20 but there are no transfers (TR-0)