(x²+y²)(x²+y²-1)=12 x²+y²=
已知x+y=1,xy=-二分之一,求x(x+y)(x-y)-x(x+y)²
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
[(y-2x)(-2x-y)-4(x-2y)²]*2y,其中x=1,y=2
因式分解:x²(x-y)+(y-x)
1、y-x/x²-y²
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
x²+xy/(x-4y)(x+y),其中x=4,y=-1
[2x²-(x+y) (x-y)] [(-x-y) (y-x)+2y²] 其中x=1,y=2
化简求值 【2x²-(x+y)(x-y)][(x+y-1)(x-y+1)+1-2y],其中x=-1,y=-2
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²