(2x-y+1)(2x+y-1)
计算:1/(2x) - 1/(x+y)((x+y)/(2x) - x - y)
1、x(x-y)(x+y)-x(x+y)^2
分式的加减:[(x/y-y/x)除以(x+y)+x(1/y-1/x)]除以1+x/y,其中x=5,y=2
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
(1)(x^2/x)-y-x-y
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
(x-2y)2n÷(2y-x)2n-1+(2x-y)(-2x-y)+(x-y)(-x+y)
1) (x+y)^2-(x+y)^3 2) (x-y)^2-(x-y)^3 3)(x-y)^2-(y-x)^3 因式分解
(2X-Y)²-4(X-Y)*(X+Y)-(X-Y)*(X-1)
先化简再求值:(x-2y)²-(x+2y)(x-2y)-(x-3y)(x-y).其中x²+9y
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
先化简,再求值 (1)[(x-y)的平方+(x+y)(x-y)]÷2x 其中X=2010,y=2009 (2)y(x+y