已知等差数列前n项和为Sn ,若S13〈0 ,S12〉0,则此数列中绝对值最小项是

已知等差数列{an} 的前n项和为Sn,若S12>0,S13 已知等差数列An的前n项和为Sn,且S13>0,S14 设等差数列{an}的前n项和为Sn,已知S12>0,S13 设等差数列的前n项和为Sn,已知：A3=12,S12>0,S13 已知等差数列an的前n项和为Sn,若a2+a12=8,则S13= 等差数列前n项和为Sn 若a2+a8+a11=30 s13=? 已知等差数列前n项和为Sn ,若S13〈0 ,S12〉0,则此数列中绝对值最小项是 设等差数列an 的前n项和为sn已知a3=12 S12>0 S13 设等差数列｛an｝的前n项和为Sn,已知a3=12,S12>0,S13 设等差数列{an}的前n项和为Sn,已知a3=12,S12>0,S130,S13 设等差数列{an}的前n项的和为Sn,已知a3=12,S12>0,S13 设等差数列{an}的前n项和为Sn,已知a3=12,且S12>0,S13 已知等差数列前n项和为sn a1＋a9＋a11等于30求s13 设等差数列{An}的前n项和为Sn ,已知a3=12 S12>0 S13 设等差数列an的前n项和为sn已知a3=12 s12大于0 s13小于0 设等差数列{an}的前n项和为Sn,已知a3=12,S12>0,S13 已知等差数列{α n}的前n项和为Sn,若a2＋a7＋a12＝24,则S13 急, 设等差数列前n项和Sn 已知a3=12 S12>0 S13