How can I know the impact of the increase in one unit of G or T on the multipliers? Do I need to use differentiation to find the answer for question (e)?

The following equations refer to the goods market of an economy in billions of euros: C = 480 + 0.5YD I = 110 T = 70 G = 250 (a) Solve for the goods market equilibrium. (b) Find equilibrium disposable income (YD). (c) Find equilibrium consumption (C). (d) Calculate the private savings, public savings, and investment spending. (e) Calculate the multipliers in the following cases. (i) The government increases G by one unit, while T does not change AY AG (ii) The government increases T by one unit, while G does not change AY AT (111) The government increases G and T by one unit AY AG AG=AT )