已知x2+xy=4,xy+y2=12,求代数式x2-y2与x2+2xy+y2的值各为多少格式正确

已知x2+xy=4,xy+y2=12,求代数式x2-y2与x2+2xy+y2的值各为多少格式正确 已知x2-3xy=-5,xy+y2=3,求x2-2xy+y2. 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 已知X2+y2=7,Xy=-2,求多项式5X2一3Xy-4y2-11Xy-7X2+2y2的值. 已知x2+y2+4x-2y+5=0,求x2+2xy+y2值 已知x/y+y/x=2,求(x2+xy+y2)/(x2-4xy+y2)的值 已知x+y=5,xy=-12,求代数式x2-xy+y2 已知x+y=4,xy=2,求x2+y2+3xy的值. 已知x满足2x2+4x+y2=2xy-4 求：xy 已知:x2+y2=4xy,求(x4+y4)÷(xy)2 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 解方程组x2+xy=12 xy+y2=4 已知x2+y2=12,x+y=4,求xy的值 已知x-y=4,x2+y2=12,求xy的值 已知X2次方+XY=3,XY+Y2次方=-2,求下例值:X2次方+4XY+3Y2次方 已知x2+xy=3,xy+y2=-2,则2x2-xy-3y2= x2-y2=xy,xy不等于0求x2/y2=y2/x2