如果x2+xy=2,xy+y2=-1,则x2-y2=------,x2+2xy+y2=------.

学习 时间:2026-09-29 18:43:26 阅读:5373
如果x2+xy=2,xy+y2=-1,则x2-y2=______,x2+2xy+y2=______.

最佳回答

玩命的紫菜

称心的大侠

2026-09-29 18:43:26

(1)∵x2-y2=x2+xy-xy-y2=x2+xy-(xy+y2)而x2+xy=2,xy+y2=-1,∴x2-y2=2-(-1)=3;(2)∵x2+2xy+y2=x2+xy+xy+y2,而x2+xy=2,xy+y2=1,∴x2+2xy+y2=x2+xy+xy+y2=2-1=1;故答案为:3,1.

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  • 感动的灯泡
    回复
    2026-09-29 18:43:26

    (1)∵x2-y2=x2+xy-xy-y2=x2+xy-(xy+y2)而x2+xy=2,xy+y2=-1,∴x2-y2=2-(-1)=3;(2)∵x2+2xy+y2=x2+xy+xy+y2,而x2+xy=2,xy+y2=1,∴x2+2xy+y2=x2+xy+xy+y2=2-1=1;故答案为:3,1.

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