已知2x-y=1/4 XY=3求4X^3Y-4X^2Y^2+XY^3的值

问题描述:

已知2x-y=1/4 XY=3求4X^3Y-4X^2Y^2+XY^3的值
我很急啊~~~~~~~~马上就要要

4x^3y-4x^2y^2+xy^3
=xy(4x^2-4xy+y^2)
=xy(2x-y)^2
=3×(1/4)^2
=3/16