求（x^2+y^2）-4x^2y^2

求因式分解(x-y)²-2(x-y)³和（x+y）（x-y）-x（x-y） 如果|X|=4 |Y|=2 且|X+Y|=X+Y 求X+Y 已知（x+y）2 =2,(x-y)3 =3,求(x+y)7(x-y)2(x+y)3(y-x)4 的值 2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y 求y''+2y'+y=e^-x/x的通解y''+2y'+y=（e^-x）/x 已知2y-x=-3,求[4y(2x-y)-2x(2x-y)]/(2x-y 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 RT,若（√2x-y）+y^2+4y+4=0,求[(x-y)^2+(x+y)(x-y)]÷2x的值 已知x²-y²=10,求[（x+y）³-2y(x+y)²-4(x+y)]÷(x+y)的值 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 已知：【（x²+y²）-（x-y)²+2y（x-y)】÷4y=,求4x/（4²-y²）-1/（2x+y)的值已知：【（x²+y²）-（x-y)²+2y（x-y)】÷4y=1，求4x/（4²-y²）-1/（2x+y)的值 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x-y=1,求[(x+2y)^2+(2x+y)(x-4y)-3(x+y)(x-y)]除以y的值大神们帮帮忙 已知:【(x²+y²)-(x-y)²+2y(x-y)】/4y=1,求4x/4x²-y²-1/2x+y 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 [(x+y)(x-y)-(x-y)²+2y(x-y)]÷4y