C129的知识精选

记,则的值为  A.1                  B.2                  C.129...
问题详情:记,则的值为  A.1                  B.2                  C.129                D.2188【回答】C【解析】【详解】中,令,得.∵展开式中∴故选C.点睛:二...
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