化简(2x/(x+y)一4x/(y-x))÷8x/(x^2-y^2)

1、x(x-y)(x+y)-x(x+y)^2 化简：（2x-y)²-4(x-y)(x+y) 化简：[(2x-y)平方+（2x+y)(2x-y)-4x(x-y+1)]÷2x [x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 x^2-y^2/x+y-4x(x-y)+y^2/2x-y, (1)(x^2/x)-y-x-y [(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y 【(x-y)^2+(x+y)(x-y)】除以 2x x/x-y*y^2/x+y-x^3y2/x^4-y^4/x^2/x^2+y^2 1.[(x-y)^2-2(y -x)]÷(x-y) (2x-y)^2-4(x-y)(x+2y)