因为等差数列的前9项的均值等于第五项
a5:b5=S9：S9''
n=9带入Sn:Sn''=5n+3:2n+7,
得a5:b5=48：25
等差数列an,bn的前n项和的比为Sn:Sn''=5n+3:2n+7,则a5:b5=?
3个回答
相关问题
-
等差数列an,bn的前n项和Sn,Tn满足Sn/Tn=3n+1/2n+5,则a5+b3=
-
等差数列{an}{bn},前n项和分别为Sn,Tn,Sn/Tn=n+4/4n+3,则a5/b5=?
-
设Sn ,Tn分别为等差数列{an}{bn}的前n项和,Sn/Tn=(5n-2)/(n+3),则an/bn=?
-
an和bn是等差数列,其前N项和为sn和tn,若sn比tn等于7n+2比n+3求a5比b5则
-
等差数列{an},{bn}的前n项和分别为Sn,Tn,且Sn/Tn=(2n-1)/(3n+2),则a5/b5
-
等差数列{an},{bn}的前n项和分别为Sn,Tn,Sn/Tn=2n/3n+1则a3/b5
-
等差数列{an},{bn}的前n项和Sn,Tn满足Sn/Tn=3n+1/2n+5则a5/b5=___,a3/b3=___
-
等差数列{an}和{bn}前n项和为sn,Tn且sn/tn=2n+1/n+2求a5/b5
-
等差数列{An},{Bn}的前n项和为Sn与Tn,若Sn/Tn=2n/3n+1,则A5/B7的值是
-
等差数列{an}和{bn}的前n项和分别为Sn和Tn,且Sn/Tn=2n/3n+1,则a3/b5=