如果M=3x2-2xy-4y2,N=4x2+5xy-y2,则8x2-13xy-15y2等于( )
如果M=3x2-2xy-4y2,N=4x2+5xy-y2,则8x2-13xy-15y2等于( )
已知x2-xy=-3,2xy-y2=-8,求2x2+4xy-3y2的值.
已知x2+y2=7,xy=-2,求5x2—3xy—4y2—11xy—7x2+2y2的值
已知X2+y2=7,Xy=-2,求多项式5X2一3Xy-4y2-11Xy-7X2+2y2的值.
已知:x2+y2=7,xy=-2.求7x2-3xy-2y2-11xy-5x2+4y2的值.
已知x2+y2 =7,xy=-2.求5x2 -3xy-4y2 -11xy-7x2 +2y2
已知6x2减去xy减去15y2等于0,求分式2x2减去3xy减去3y2分之x2减去2xy+4y2
已知:x2+y2=7,xy=-2.求7x2-3xy-2y2-11xy-5x2+4y2已知:x2+y2=7,xy=-2.求
已知x2+xy=3,xy+y2=-2,则2x2-xy-3y2的值为( )
已知x2-xy=7,2xy+y2=4,则代数式x2+xy+y2的值是___.
已知,A=3x2+3y2-5xy,B=2xy-3y2+4x2,求:
(2x2-3xy+4y2)+(x2+2xy-3y2)化简(要有过程)