(x²+y²）²-4x²y²=?

2.(x+y)²(x-y)²-(x-y)(x+y）(x²+y²) 若|x+2y-1|+y²+4y+4=0,求（2x-y）²-2（2x-y)(x+2y)+(x+2y)& （x-2y）²+（2x-4y)(x+y)+(x+y)² 已知x²+y²-8x+6y+25=0,求（x-y+4xy/x-y）（x+y-4xy/x+y） (2x-y)²-4(x-y)(x+2y) 化简：（2x-y)²-4(x-y)(x+y) 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² (x+y)²+4(x+y)-5 （x-2y)(x²-4y²）（x+2y)=什么? 已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y 因式分解:x²(x-y)+(y-x) [(y-2x)(-2x-y)-4(x-2y)²]*2y,其中x=1,y=2