已知|x+2y+1|+(-y-2)²=0,求(2x-y)²-2(2x-y)(x+2y)²
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
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
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
已知x²+y²+5=2x+4y,求代数式(2x²-(x+y)(x-y))x((x+y-1)
已知x²+y²-2x+4y+5=0,求x+y
已知x²+4x+y-2y+5=0求x+2y
已知y-2x=0,求3x²-2y²/(x+y)(x-y)的值
已知实数x, y满足x²+y²-2x+6y+10=0,求y∧-x.
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+13-4x+6y=0,求(2x-y)²-2(2x-y)(x+2y)+(x+
已知4x=9y求(1)x+y/y (2)y-x/2x