{an}等比前N项和为Sn,若S3分之S6等于4,求S6分之S12
设Sn是等差数列An的前n项和,若S3/S6=1/3,则S6/S12等于
设等比数列{an}的前n项和为sn,若S6,S9,S3成等差数列,问2S3,S6,S12-S6S能否成等比数列?请说明理
设Sn是等差数列{an}的前n项和,若S3/S6=1/3,则S6/S12等于——
设sn是等比数列{an}的前n项和,是s3/s6=1/3.则s6/s12=
设Sn是等差数列『An』的前n项和,诺S3/S6=1/3,则S6/S12的值等于
1.设等比数列{an}的前n项和为Sn,若S6/S3=3,则S9/S6=?
设等比数列an的前n项的和为Sn,若S6/S3=3,则S9/S6=
等比数列{an}的前n项和为sn,若S3,S9,S6成等差数列,求此数列的公差,
以知数列{An}是等比数列.公比Q不等于1,Sn是其前n项和,a1,a7,a4成等差数列.求证2S3,S6,S12-S6
设Sn是等差数列{an}的前N项和,诺S3/S6=1/3则S6/S12=多少
已知等比数列an的前n相和为Sn,S3=2,S6=6, 则S12= 求详解
设等比数列{an}的前n项和为Sn,若S6:S3=1:2,则S9:S3=?