已知Sn是等比数列的前n项和,m是正奇数若SmS3mS2m成等差数列,问ama3ma2m如何排序可成等差数列?（注：m,

已知Sn是等比数列的前n项和,m是正奇数若SmS3mS2m成等差数列,问ama3ma2m如何排序可成等差数列?（注：m, 已知Sn是等比数列{an}的前n项和,a3、a9、a6、成等差数列,问 设Sn是等差数列｛an｝的前n项和,求证：若正整数m,n,p成等差数列,则Sm/m,Sn/n,Sp/p也成等差数列. 已知Sn是等比数列｛an}的前n项和,a2.a8,a5成等差数列 已知Sn是等比数列{An}的前N项和,S3,S9,S6成等差数列,则 等差数列〔an 〕的前n 项和为Sn,已知Sm等于a ,Sn 减Sn-m 等于b ,n ,m 是正的 关于等差数列基础题已知Sn是 等比数列An的前n项和,S3,S9,S6成等差数列,求证 A2,A8,A5成等差数列（步骤 设Sn是等比数列的前n项和,S3,S9,S6成等差数列 求证a2,a8,a5成等差数列 设Sn是等比数列{an}的前n项和，S3，S9，S6成等差数列． 已知Sn是等比数列{an}的前n项和,设公比为q,且S3,S9,S6成等差数列. 已知等比数列{an}的前n项和为Sn,若am,am+2,am+1(m∈R)成等差数列,试判断Sm,Sm+2,S 已知Sn是等比数列an的前n项和,S4S10S7成等差数列,若a1=1,求数列an^3的前n项的积