已知 x²-xy+2y²=14,且x-y=6,求x-2y
已知 x²-xy+2y²=14,且x-y=6,求x-2y
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x+y,且x²-2x=7,y²-2y=7求①x+y②2x+xy+y²
已知x/y=2,求x²-xy+3y²/x²+xy+6y²的值
已知x>0,y>0,且x+6y=5根号xy,求(2x+根号xy-y)分之(x+根号xy+2y)的值
已知x-7y=0,且y≠0,求2x²﹢xy-3y²分之x²-3xy+y²的值
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y
已知x≠y,且x²-x=2,y²-y=2,求x²-xy+y²的值
已知xy不等于0,且3x² -2xy-8y²=0,求x/y的值
已知,xy≠0,且3x²-2xy-8y²=0,求x/y的值
已知xy=-2,x-y=3,求(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)÷2y
已知|x|=6,|y|=2,且|x+y|=﹣(x+y),求xy值.