x2-y2=55,x-y=5,则x+y=______.
x2-y2=55,x-y=5,则x+y=______.
已知x2+4x+y2-2y+5=0,则x2+y2=______.
已知x2-4y2=20,x+2y=5,则x=______,y=______.
若实数x,y满足3x2+2y2=6x,则x2+y2的最大值为______.
已知x-y=5,(x+y)2=49,则x2+y2的值等于______.
已知实数x,y满足2x-y-5=0,则x2+y2的最小值为______.
已知x-y=2,则x2-y2-4y=______.
已知x+y=5,xy=3 则x2+y2=______.
若x+y=5,xy=6,则x2+y2=______.
已知x+y=-5,xy=6,则x2+y2=______.
若x2-4x+y2+6y+13=0,则x=______,y=______.
如果x+y=-1,x-y=-3,那么x2-y2=______.