x²+y²-2x-2y+1=?
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
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
[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x²+y²+5=2x+4y,求代数式(2x²-(x+y)(x-y))x((x+y-1)
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y
先化简,再求值:(3x-y)²+(3x+y)(3x-y),其中x=1,y=-2