x-y+1

1、x(x-y)(x+y)-x(x+y)^2 (1)(x^2/x)-y-x-y [(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y 1、(x-2y)(x+y) 1、y-x/x²-y² (1)(x+y)^2-(x-y)^2 1 ,化简 （x-y)(x+y) 因式分解 (1)6(x-y)^3-3y(y-x)^2 (2)x(x-y)(a-b)-y(y-x)( 1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [（x+y)(x-y)-(x-y)^2+2y(x-y 以下三个行列式的计算过程是什么.谢谢 1.x y x+y y x+y x x+y x y 2.1 x y z x 1 0 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 xy-1+x-y