已知(x=1)²+|y-2|=0求(2x²-2y²)+3(x²y²+y
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
已知y-2x=0,求3x²-2y²/(x+y)(x-y)的值
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x²+y²-2x+4y+5=0,求x+y
已知x-3y=0,求(x²-2xy+y²/x-y)-2y的值
已知x,y的值满足方程组x+2y=3,x-y=-2,求x/(x-y)²+x²-y²/(x+
已知x²+4x+y-2y+5=0求x+2y
已知x²+y²+5=2x+4y,求代数式(2x²-(x+y)(x-y))x((x+y-1)
已知x+3y=2,求代数式(x²-y²/x+y)-【2(x+y)】的值
已知实数x, y满足x²+y²-2x+6y+10=0,求y∧-x.
已知x²+x*y=-1,x*y+y²=2,试求2x²-x*y-3y²的值