化简求值:[4(xy-1)²-(xy+2)(2-xy)]÷ -1/4 xy,其中x=-2,y=1/5

题目

化简求值:[4(xy-1)²-(xy+2)(2-xy)]÷ -1/4 xy,其中x=-2,y=1/5
注意：是-1/4xy

答案

化简结果是：-20xy+32代入得40