Example The equations defining a model of two trading nations are given by Y, = C + 1 + X, - MY, = C+ I + X, - M, C = 0.87, + 200 C = 0.98, + 100 M = 0.2Y M2 = 0.18, Express this system in matrix form and hence write Y, in terms of If and 13. Write down the multiplier for Y, due to changes in If and hence describe the effect on the national income country 1 due to changes in the investment in country 2