4x²y²/(-1/2x²y)
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
(x-2y)²+(2x-4y)(x+y)+(x+y)²
【(X²+Y²)-(X-Y)²+2Y(X-Y)】/4Y=1,求4X/4X²-Y&
(2x-y)²-4(x-y)(x+2y)
化简:(2x-y)²-4(x-y)(x+y)
因式分解 (1).(x+y)(x+y-6)+9 (2).x²-16y²-x-4y
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
[(y-2x)(-2x-y)-4(x-2y)²]*2y,其中x=1,y=2
计算:(1)2/(x+y)+4y/x²-y²(2)x²/x+y-x+y
(3x-y)²-2x(4x-5y)-(x+2y)²
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.