多项式2(x2-3xy-y2)-(x2+2mxy+2y2)中不含xy项,则m=______.
多项式2(x2-3xy-y2)-(x2+2mxy+2y2)中不含xy项,则m=______.
当m=______时,多项式3x2+2xy+y2-mx2中不含x2项.
要使多项式2mxy-xy+1-2x2-4mxy+5x2+7xy中不含xy项,则m的值为______.
如果M=3x2-2xy-4y2,N=4x2+5xy-y2,则8x2-13xy-15y2等于( )
已知x2+xy=3,xy+y2=-2,则2x2-xy-3y2=______.
一个多项式A与多项式B=2x2-3xy-y2的差是多项式C=x2+xy+y2,则A等于( )
已知x2+xy=3,xy+y2=-2,则2x2-xy-3y2的值为( )
如果x2+xy=2,xy+y2=-1,则x2-y2=______,x2+2xy+y2=______.
已知x+y=4,xy=2,则x2+y2+3xy=______.
已知X2+y2=7,Xy=-2,求多项式5X2一3Xy-4y2-11Xy-7X2+2y2的值.
当k=______时,多项式2x2-4xy+3y2与-3kxy+5的和中不含xy项.
若(2x+y)(x-2y)=2x2-mxy-2y2,则m=______.