Find the equilibrium level of GDP(income or Y) demanded in an economy in which investment (I) is always $300, net export (X-IM) are always -$50, government expenditures (G) and taxes (T) are each equal to $400, and consumption function is described by the following algebraic equation:

C= 150 + 0.75DI,

DI is disposable income

1. much saving (S) is there at the equilibrium level of income.

Hint: DI=Y (national income or GDP) minus taxes (Y-T)

1. Income (Y) not consumed (C) must be saved (S). This means that S=Y-C.
2. Demand (AD). That would be the equilibrium level of GDP or income (Y). That is the equilibrium level of income (real GDP or Y) will be where Y = AE.

Set Y = AE or Y = C + I + G+ (X - M), and solve for Y. then solve for S.