设sn是等差数列an的前n项和,S5=3(a2+a8),则a5/a3的值

设Sn是等差数列an的前n项和,若S5/S3=5/9,则S9/S5= 设sn是等差数列an的前n项和,S5=3(a2+a8),则a5/a3的值 设｛an｝是等差数列前n项和为Sn,若S4>=10,S5 设等差数列an的前n项和为Sn,若S4>=10,S5 设等差数列an,的前n项和为Sn,a2+a4=6,求S5 设Sn是等差数列an的前n项和,a5=5a3,则S9/S5=? 设Sn是等差数列{an}的前n项和,且a1=7,S5=15. 设Sn是等差数列an的前n项和,若a5/a3=5/9,则S9/S5= 设sn是等差数列{an}的前n项和,若s9/s5=9/5,则a5/a3= 设sn是等差数列an的前n项和 a6/a3=10/7 则s11/s5= 设Sn是等差数列{an}前n项和 若a6/a3=2/3 则S11/S5= 设数列{An}是等差数列,且A2=-6,A8=6,Sn是数列{An}的前n项和,则A.S4〈S5 B.S4=S5 C.S6〈S5 D.S6=S5 等差数列{an}的前n项和为Sn,且S10-S5=3,S15=? 设sn是等差数列an的前n项和,s5=3（a2+a8）则a5/a3的值为 设等差数列{an}前n项和为Sn,a3=4.则S5= 已知Sn表示等差数列an的前n项和且S5/S10=1/3 求S5/S20=? 设Sn是等差数列an的前n相和,且a1=1,a4=7.S5? 设等差数列{an}的前n项和为Sn,且S5=-5,S10=15,求数列{Sn/n}的前n项和Tn