化简:(2x-y)^2-2(2x-y)(2x+y)+(2x+y)^2,并求当|x+2y-1|+(2x-y-2)^2=0,

1、x(x-y)(x+y)-x(x+y)^2 (1)(x^2/x)-y-x-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) [(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 已知4x=9y求(1)x+y/y (2)y-x/2x 当x+y/x-y=1/2时,求代数式x-y/x+y-2x+2y/x-y的值 [x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013 【(x-y)^2+(x+y)(x-y)】除以 2x 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 将x（x+y）（x-y）-x（x+y）2进行因式分解，并求当x+y=1，xy＝−12