若x-y=3,x2+y2=13/2,则x+y=
若实数x,y满足3x2+2y2=6x,则x2+y2的最大值为______.
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
已知x2+y2+4x-6y+13=0 求x2-2x\x2+3y2
若x-y=2,x2-y2=10,则x+y= ___ .
已知x2+y2-6x+4y+13=0,求2x+3y
若实数x,y满足X2+y2-2X+4y=0,则x-2y的最大值为?
实数x、y满足3x2+2y2=6x,则x2+y2的最大值为( )
我做对了吗.x2(x-y)+y2(y-x)= x2(x-y)-y2(x-y)=x2-y2=(x+y)(x-y)
解方程组:y2=x3-3x2+2x;x2=y3-3y2+2y
已知x2+4x+y2-2y+5=0,则x2+y2=______.
已知:x=3,y=-5,x2-2xy+y2/x2-y2的值是
若X2+Y2-2X-6Y+10=0 ,求(x2-y2)/xy的值