请教一道简单宏观模型用微分来解的题，多谢！

A standard macroeconomic model consists of these two equations:

M = lPY + L(r) and S(y,r,g) = I(Y,r)

M, l and P are positiveconstants, and L, S, Iare differentiable functions. Assume that gis a parameter. Differentiate the system and find expressions for dy/dg and dr/dg.

两边全微分 然后用cramer rule...

同求~~~~该不是我同学吧~~~

这个问题是simultaneous的几个隐函数的式子求导，先把各个式子全导，写成矩阵形式，然后用cramer rule，可以参考经济数学的书的讲隐函数的部分，多谢楼上回复。