设等比数列{an]的公比为q,前n项和为Sn,且S10=8,则(S20)/(1+q^10)=
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![设等比数列{an]的公比为q,前n项和为Sn,且S10=8,则(S20)/(1+q^10)=](/uploads/image/z/10217496-48-6.jpg?t=%E8%AE%BE%E7%AD%89%E6%AF%94%E6%95%B0%E5%88%97%7Ban%5D%E7%9A%84%E5%85%AC%E6%AF%94%E4%B8%BAq%2C%E5%89%8Dn%E9%A1%B9%E5%92%8C%E4%B8%BASn%2C%E4%B8%94S10%3D8%2C%E5%88%99%EF%BC%88S20%EF%BC%89%2F%EF%BC%881%2Bq%5E10%29%3D)
设等比数列{an]的公比为q,前n项和为Sn,且S10=8,则(S20)/(1+q^10)=
设等比数列{an]的公比为q,前n项和为Sn,且S10=8,则(S20)/(1+q^10)=
设等比数列{an]的公比为q,前n项和为Sn,且S10=8,则(S20)/(1+q^10)=
s10=8=a1(1-q^10)/(1-q)
a1(1-q^10)=8*(1-q)
(S20)/(1+q^10)
=a1(1-q^20)/(1-q)/(1+q^10)
=a1(1-q^10)
=8(1-q)