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#b97595eb-58ab-4b08-81d4-1c3a9fd92cd6简单解答题等差数列的概念与通项数列

11.记SnS_{n}为等差数列{an}\{a_{n}\}的前nn项和.若S3=9S_{3}=9S6=36S_{6}=36,则S12=S_{12}=[ 144 ].