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#b5503011-93ee-4070-9c50-2545f4e78928基础填空题等差数列的概念与通项数列

2.已知等差数列{an}\{a_{n}\},其前nn项和SnS_{n}满足S7a4=12S_{7}-a_{4}=12,则a2+a6=(a_{2}+a_{6}=(  ))