(x-y+1)^2-(x+y-3)^2

1、x(x-y)(x+y)-x(x+y)^2 因式分解 (1)6(x-y)^3-3y(y-x)^2 (2)x(x-y)(a-b)-y(y-x)( 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y (1)(x^2/x)-y-x-y (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 （x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3) {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 [(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y 2(x+y) 3x+3y=24 x+y/2x x y/2y= 1 1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y) 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 【x-3y][x+y]-[x-2y][x +2y]-[x-y