5x2-3xy-4y2-11xy+(-7x2)-(-2y2),其中x2+y2=7,xy=-2,求值

已知x2+y2 =7,xy=-2.求5x2 -3xy-4y2 -11xy-7x2 +2y2 已知x2+y2=7,xy=-2,求5x2—3xy—4y2—11xy—7x2+2y2的值 5x2-3xy-4y2-11xy+(-7x2)-(-2y2),其中x2+y2=7,xy=-2,求值 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已知:x2+y2=7,xy=-2.求7x2-3xy-2y2-11xy-5x2+4y2 (x2+xy+y2)-4xy(x2+y2) 若3x2-4xy+y2=-3,2x2+3xy-2y2=8,求5x2-18xy+7y2的值. 4x2-3y2+2xy-4x2+5x2 多项式x2-3xy+2y2-2加上( )等于5x2-7xy-3y2 已知x2-3xy=-5,xy+y2=3,求x2-2xy+y2. x2-4y2-3xy+y+x x2+3xy-4y2因式分解 x2+4xy+3y2分解因式, 4x2+3xy-2y2因式分解 X2-3xy-4y2因式分解 告诉 因式分解：3x2+4xy-y2 3x2+4xy-y2因式分解 3x2-4xy+y2 因式分解