设等差数列﹛an﹜﹛bn﹜的前n项和分别为Sn,Tn.且Sn/Tn=n-9/5n-9.则a8/b8=?

设﹛an﹜是等差数列,Sn是其前n项和,求证:以bn=Sn／n﹙n∈N*)为通项公式的数列﹛bn﹜是等差数列 设等差数列﹛an﹜﹛bn﹜的前n项和分别为Sn,Tn.且Sn/Tn=n-9/5n-9.则a8/b8=? 已知两个等差数列{an}和{bn}的前n项和分别为An和Bn, 两等差数列﹛an﹜﹛bn﹜前n项和之比为5n+3/2n+7.则an/bn的值为? 等差数列{an},{bn}的前n项和分别为An,Bn,切An/Bn=2n/3n+1,求lim(n→∞)an/bn 设﹛an﹜为等差数列,﹛bn﹜为等比数列,a1=b1=1,a2+a4=b3,b2b4=a3分别求出﹛an﹜及﹛bn﹜的前10项S10和T10 计算等差数列{an}{bn}的前n项和分别为An.Bn,且An/Bn=2n/(n+1)求limn→∞(an/bn) 设Sn是等差数列,﹛an﹜的前n项和Sn＝－3n²/2＋205n/2,构造新的数列﹛bn﹜ ,令bn＝|an|,求数列﹛bn﹜的前n项和Tn, 已知等差数列﹛an﹜的前n项和为Sn,且a3=5,S6=36,bn=2an×2的an次方求数列﹛bn﹜的前n项和Tn 已知数列{an}是公差为正数的等差数列,数列{bn}是首相为1的等比数列,设cn＝an×bn,且数列﹛cn﹜的前三项依为1,4,12.﹙1﹚求数列{an},{bn}的通项公式；﹙2﹚若数列{an}的前n项和为Sn,求数列﹛Sn／n﹜ 设数列{an}是等差数列,数列﹛bn﹜的前n项和为Sn=2/3（bn-1）,若a2=b1,a3=b2.求 ：⑴数列{an}的通项公式；⑵数列{bn}的前n项和Sn. 设数列﹛an﹜的前n项和为Sn,已知a1=8,an+1=Sn+3^(n+1)+5,n∈N*.设bn=an-2*3^n,证明﹛bn﹜是 等比数列 等差数列{an}{bn}的前n项和分别为An,Bn,An/Bn=7n+1/4n+27,a5/b5=? 等差数列｛an｝,｛bn｝的前n项和分别为An,Bn,An／Bn＝7n＋1／4n＋27,a5／b5等于多少 两个等差数列{an}{bn}的前n项和分别为An,Bn且An/Bn=(n-3)/(3n+1)则a6/b6 等差数列{an},{bn}的前n项和分别为An,Bn,且An/Bn＝7n+45/n+3,则a5/b5等于? 设两个等差数列{an},{bn}的前n项和分别为Sn,Tn.若Sn/Tn=7n+1/4n+27,则a7/b7= 两等差数列﹛an﹜﹛bn﹜前n项和之比为5n+3/2n+7.则a5/b5的值为?