已知x2+xy=5,xy+y2=-1,则x2-y2=______.
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已知x2+xy=5,xy+y2=-1,则x2-y2=______.
![已知x2+xy=5,xy+y2=-1,则x2-y2=______.](/uploads/image/z/6818353-25-3.jpg?t=%E5%B7%B2%E7%9F%A5x2%2Bxy%3D5%EF%BC%8Cxy%2By2%3D-1%EF%BC%8C%E5%88%99x2-y2%3D______%EF%BC%8E)
∵x2+xy=5,xy+y2=-1,
∴(x2+xy)-(xy+y2)
=x2+xy-xy-y2
=x2-y2
=5-(-1)
=6.
故填:6
∴(x2+xy)-(xy+y2)
=x2+xy-xy-y2
=x2-y2
=5-(-1)
=6.
故填:6
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