已知x2+y2-2xy-6x+6y+9=0,求x-y的值

已知x2+4y2+x2y2+1=6xy,则(x4-y4)/(2x2+xy-y2)*(2x-y)/(xy-y2)/(x2+y2/y)2= 已知X2-2x+y2+6y+10=0,求（x2-2xy）/(xy+y2)的值 已知X2+Y2+8X+6Y+25=0 求代数式X2++XY+4Y2分之X2-4Y2 减X+2Y分之X的值 已知：x2-y2=16,x+y=2,求：3x-3y/y2-x2+x2-2xy+y2/x2-y2-x2-x-6/x+2除以(x+y) 已知x2+y2-10x-6y+34=0,求（x-y/x+y）2÷x2-y2/xy×x2+2xy+y2/x2-xy 的值. x2-2xy+y2=4 x2+y2-x-y=6 解不等式x2-2xy+y2=4 x2+y2-x-y=6 解不等式 已知xy满足x2+y2-6x+2y+10=0,求立方根号x2-y2的值 已知x2+4y2+x2y2-6xy+1=0,求 x4-y4/2x-y 乘 2xy-y2/xy-y2 除以（x2+y2/xy）2乘1/x+y的值 已知x2+y2-2xy-6x+6y+9=0,求x-y的值 已知X2+2XY+Y2-6X-6Y+9=0,求X+Y的值 若X2+Y2-2X-6Y+10=0 ,求（x2-y2)/xy的值 已知x+y=6,xy=2,则1/x2+1/y2= 已知x(x-1)+(y-x2)=6,则代数式x2+y2/2-xy的值是 已知x2-3xy-4y2的绝对值+2倍根号x2+4xy+4y2-1=0 求3x+6y的值 已知x2+y2+4x-2y+5=0,求x2+2xy+y2值 已知代数式（x+y-6）2+根号x2-4xy+4y2的值为0,则x-yx-y= ,x2+y2= . 已知x/y+y/x=2,求(x2+xy+y2)/(x2-4xy+y2)的值 已知︱x+y-2︱+(2xy-1)2=0,求x2+6xy=y2的值