已知x-y=5,(x+y)2=49,则x2+y2的值等于______.
已知x-y=5,(x+y)2=49,则x2+y2的值等于______.
已知x2+4x+y2-2y+5=0,则x2+y2=______.
已知实数x、y满足(x2+y2)(x2+y2-1)=2,则x2+y2的值为______.
已知x2+y2=25,x+y=7,且x>y,则x-y的值等于______.
(选做题)已知x+2y=1,则x2+y2的最小值是______.
已知实数x,y满足2x-y-5=0,则x2+y2的最小值为______.
已知x2-4y2=20,x+2y=5,则x=______,y=______.
已知2x+y=7,x2+y2=5,求(4x+2y)2-3x2-y2+2(1-y2)的值.
已知实数x、y满足x2+4xy+4y2+x+2y-6=0,则x+2y的值为______.
已知x-y=5,(x+y)2-49,求X2+y2的值
已知:x+y=4,x2-y2=20,则x-y的值是______.
已知x2+4x+y2-2y+5=0,求x,y的值.