1/2x-y-2/x-y
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
计算:(1)2/(x+y)+4y/x²-y²(2)x²/x+y-x+y
已知x-y=1,y≠0,求{(x+2y)²+(2x+y)(x+4y)-3(x+y)(x-y)}÷y的值.
已知x+y=1,xy=-2分之1,利用因式分解求:x(x+y)(x-y)-x(x+y)²的值
(1)(x+y)^2-(x-y)^2
1、(x-2y)(x+y)
先化简,再求值:x²/x-y-y²/x-y,其中x=1+2又根号3
1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [(x+y)(x-y)-(x-y)^2+2y(x-y
因式分解 (1)6(x-y)^3-3y(y-x)^2 (2)x(x-y)(a-b)-y(y-x)(
[(2x+y)²-y(y+4x)-8x] ÷2x 其中x=2,y=-1