[(x+2y)^2-(x-y)(x+2y)-5y^2]÷(2y)

[(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y [x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013 1、x(x-y)(x+y)-x(x+y)^2 1.[(x-y)^2-2(y -x)]÷(x-y) 数学(x-y)^5*(y-x)^3*(x-y)^2 [(x+2y)^2 -(x+y)(3x-y)-5y^2]÷2x 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) （X+2Y)(5X-2Y) (2X-3y)-(5x-y) 【(x-y)^2+(x+y)(x-y)】除以 2x (1)(x^2/x)-y-x-y 1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [（x+y)(x-y)-(x-y)^2+2y(x-y