1.等差数列{an},{bn}的前n项和分别为Sn,Tn,（1）若Sm=n,Sn=m,求Sn+m（2）若Sn/Tn=(7n+1)/(4n+27),求an/bn2.已知等差数列{an}中,公差d>0,其前n项和为Sn,且满足a2xa3=45,a1+a4=14,（1）通过bn=Sn/(n+c)构造一个新的数列{

等差数列{an}的前n项和为An,等差数列{bn}的前n项和为Bn若Bn/An=n/3n+1 1.求a5/b5 2 an/bn 已知两个等差数列{an}和{bn}的前n项和分别为An和Bn, 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 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) {an}等差数列,an=21-2n,bn=|an|,求{bn}的前n项和Tnxx a1=1.an+1=2an+2^n.bn=an/2^n-1.证明bn是等差数列、求数列的前n项和sn? 等差数列除以等比数列 an=n bn=2^n-3 求an除以bn的前n项和 已知等差数列{an}和{bn},他们的前n项之和为An和Bn,若An/Bn=(5n+3)/(2n-1)A9/B9 等差数列{an}的前n项和sn=an^2+bn+c,则c= 已知{an},{bn}均为等差数列,前n项的和为An,Bn,且An/Bn=2n/(3n+1),求a10/b10的值 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项和为An,Bn,且An/Bn=n/3n-2,则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? 若两个等差数列｛an｝、{bn}的前n项和An、Bn,且满足An/Bn=(4n+2)/(5n-5),则a13/b13 已知数列an的前n项和为sn,且sn=n^2-16n n∈ N*1.求证an是等差数列2.记bn=绝对值an,求数列bn的前n项和Tn 数列Cn=Bn*An,Bn是等差数列,An是等比数列,怎么求Cn的前n项和?