(-1/2 x^2 y)^-2 / (- 2/3 x y^2 )^-2
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
因式分解 (1)6(x-y)^3-3y(y-x)^2 (2)x(x-y)(a-b)-y(y-x)(
化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方
【x-3y][x+y]-[x-2y][x +2y]-[x-y
[(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y)
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
有这样一道题:"计算(2*x*x*x-3*x*x*y-2*x*y*y)-(x*x*x-2*x*y*y+y*y*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