若(2x+y)(x-2y)=2x2-mxy-2y2,则m=______.
若(2x+y)(x-2y)=2x2-mxy-2y2,则m=______.
已知x2+4x+y2-2y+5=0,则x2+y2=______.
若实数x,y满足3x2+2y2=6x,则x2+y2的最大值为______.
多项式2(x2-3xy-y2)-(x2+2mxy+2y2)中不含xy项,则m=______.
已知实数x、y满足(x2+y2)(x2+y2-1)=2,则x2+y2的值为______.
若(x+y)2=25,(x-y)2=1,x2+y2的值是______.
已知x+y=4,x2+y2=10,则(x-y)2=______.
已知x-y=5,(x+y)2=49,则x2+y2的值等于______.
(选做题)已知x+2y=1,则x2+y2的最小值是______.
已知x-y=2,则x2-y2-4y=______.
已知x、y是实数且满足x2+xy+y2-2=0,设M=x2-xy+y2,则M的取值范围是______.
已知xy=3,x2+xy-2y2=2(x+2y),且x≠-2y,则x+y=______.