已知x2 +y2=12,xy=3,且0<x<y,求(x-y)/(x+y)的值.
已知x2 +y2=12,xy=3,且0<x<y,求(x-y)/(x+y)的值.
已知x>y>0,且xy=1,求 (x2+y2)/(x-y)的最小值,
已知x>y>0且xy=1.求x2+y2/x-y的最小值及此时xy的值
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
已知x2-3xy+2y2=10,且x-y=3,求2x-y的值.
已知x+y=8,xy=12,求x2+y2;(x-y)2的值
已知xy不等于0,且3x2-2xy-8y2=0,求x/y的值?
已知2x2+5xy-3y2=0且xy不等于0,求x:y的值
已知x≠y ,x2-x=3 ,y2-y=3 ,求代数式x2+xy+y2 的值.
已知x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
已知实数x,y满足(x2)+(y2)-xy+2x-y+1=0,求x,y的值
已知实数x、y满足X2+y2-xy+2x-y+1=0,试求x、y的值