已知2x2+2xy+y2-6x+9=0,则xy的值为 ___ .
已知x2-xy=7,2xy+y2=4,则代数式x2+xy+y2的值是___.
已知2x-3*根号(xy)-2y=0(x>0),则x2+4xy-16y2除以2x2+xy-9y2的值是多少?
已知2x2+xy=6,3y2+2xy=9,求4x2+8xy+9y2的值为______.
已知x2+xy=3,xy+y2=-2,则2x2-xy-3y2的值为( )
已知X2-2x+y2+6y+10=0,求(x2-2xy)/(xy+y2)的值
已知实数x,y满足x2+4xy+4y2-x-2y+14=0,则x+2y的值为 ___ .
已知x2+xy=2,y2+xy=5,则12x2+xy+12y2=___.
已知x2-y2=xy,且xy≠0,求代数式x2y-2+x-2y2的值.
已知x、y是实数且满足x2+xy+y2-2=0,设M=x2-xy+y2,则M的取值范围是______.
已知x+y=4,xy=2,求x2+y2+3xy的值.
已知x2+y2-10x-6y+34=0,求(x-y/x+y)2÷x2-y2/xy×x2+2xy+y2/x2-xy 的值.
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值