先化简在求值[2x(x^2y-xy^2)+xy(xy-x^2)]÷(x^2y),其中x=2008,y=2007
问题描述：
先化简在求值[2x(x^2y-xy^2)+xy(xy-x^2)]÷(x^2y),其中x=2008,y=2007
答
[2x(x^2y-xy^2)+xy(xy-x^2)]÷(x^2y)=[2x*xy（x-y）+xy*x（y-x）]÷(x^2y)=[2x^2*y(x-y)-x^2*y(x-y)]÷(x^2y)=x^2*y(x-y)÷(x^2y)=x-y把x=2008,y=2007代入上式,得[2x(x^2y-xy^2)+xy(xy-x^2)]÷(x^2y)=x-y=2008-2007=...