求（x^2+y^2）-4x^2y^2

若|x+2y-1|+y²+4y+4=0,求（2x-y）²-2（2x-y)(x+2y)+(x+2y)& 求因式分解(x-y)²-2(x-y)³和（x+y）（x-y）-x（x-y） 已知4x=9y求(1)x+y/y (2)y-x/2x 2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y 已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 已知2x+y=4，求代数式[（x+y）2-（x-y）2-2y（x-12 【（X²+Y²）-（X-Y）²+2Y（X-Y）】/4Y＝1,求4X/4X²-Y& 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y