若1/x-1/y=2则分式xy/(x2-y2)的值是
已知x:Y:z=1:2:3则分式x2+y2+z2除以2xy+3yz-4xz的值是
已知x(x-1)+(y-x2)=6,则代数式x2+y2/2-xy的值是
若x2-2xy-y2-x+Y-1=0 求x-y的值
已知x+y=2,x-y=12,则分式2x2-2y2x2+2xy+y2的值是 ___ .
设x,y为实数,若4x2+y2+xy=1,则2x+y的最大值是( )
已知:x=3,y=-5,x2-2xy+y2/x2-y2的值是
已知x-y+1,X2+Y2=25 求(x+y)2和x2-xy+y2的值
设实数x,y满足x2+y2=1则 xy的取值范围是?
x(x-1)-(x2-y)=-3,求x2-y2-2xy的值
x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
已知x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
若x2+xy+y2=1且x、y∈R,则n=x2+y2的取值范围是( )