[题目]设集合A＝{1,3.a}.B＝{1.a2-a+1}.且AB.则a的值为．题目和参考答案——青夏教育精英家教网—

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【题目】设集合A＝{1,3，a}，B＝{1，a2－a＋1}，且AB，则a的值为________．

【答案】－1或2

【解析】AB，则a2－a＋1＝3或a2－a＋1＝a，解得a＝2或a＝－1或a＝1，结合集合元素的互异性，可确定a＝－1或a＝2.

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