先化简 再求值:[4(xy-1)^2-(xy+2)(2-xy)]1/4xy,其中x=-2,y=1/2

先化简 再求值:[4(xy-1)^2-(xy+2)(2-xy)]1/4xy,其中x=-2,y=1/2
先化简 再求值:[4(xy-1)^2-(xy+2)(2-xy)]1/4xy,其中x=-2,y=1/2

先化简 再求值:[4(xy-1)^2-(xy+2)(2-xy)]1/4xy,其中x=-2,y=1/2
[4(xy-1)^2-(xy+2)(2-xy)]1/4xy
=[4(x²y²-2xy+1)-(4-x²y²)]1/4xy
=(4x²y²-8xy+4-4+x²y²)1/4xy
=(5x²y²-8xy)1/4xy
=(5xy-8)1/4x²y²
∵x=-2,y=1/2
∴xy=-1
原式=(-5-8)1/4(-1)²
=-13/4