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【题目】设集合A={1,3,a},B={1,a2a+1},且AB,则a的值为________.

【答案】1或2

【解析】AB,则a2a+1=3或a2a+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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