等差数列an前n项和Sn且6S5-5S3=5,a4等于多少
等差数列an前n项和Sn且6S5-5S3=5,a4等于多少
等差数列{an}的前n项和为Sn,且6S5-5S3=5,则a4=______.
已知等差数列{an}的前n项和Sn满足S3=0,S5=-5,
已知等差数列{an}前n项和为Sn,公差d≠0,且S3+S5=50,a1,a4,a13,成等比数列,求{an}通项公式.
已知等差数列{an}前n项和为Sn,公差d≠0,且S3+S5=50,a1,a4,a13,成等比数列 设{bn/an}是首
已知等差数列{an}的前n项和伟sn,公差d≠0,且s3+s5=50,a1,a4,a13城等比数列.求数
高一数学. 已知等差数列{an}的前n项和胃Sn,公差d≠0,且S3+S5=50,a1,a4,a13成等比数列.
已知等差数列{an}前n项和为Sn,公差d≠0,且S3+S5=50,a1,a4,a13,成等比数列 (2)若从数列
已知等差数列{an}的前n项和为Sn,公差d≠0,且S3+S5=50,a1,a4,a13成等比数列.
设等差数列[an]的前n项和为Sn,若a5=5a3,则S9/S5等于多少?
数列{an}是等差数列,Sn是前n项和,a4=3,S5=25
已知等差数列﹛An﹜的前n项和为Sn,公差d≠0,且S3+S5=50,A1,A4,A13成等比数列.设﹛An分之Bn﹜是