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#40559343-9329-4349-9be4-91e68a248bf5基础填空题等差数列的概念与通项数列

14. 已知等差数列{an}\{a_{n}\}的前nn项和为SnS_{n},若S9=54S_{9}=54S8S5=30S_{8}-S_{5}=30,则S11=(S_{11}=(  ))