已知Sn,Tn分别是等差数列{an},{bn}的前n项和,且SnTn=2n+14n-2,(n∈N+)则a10b3+b18+a11b6+b15=______.-数学

题目简介

已知Sn,Tn分别是等差数列{an},{bn}的前n项和,且SnTn=2n+14n-2,(n∈N+)则a10b3+b18+a11b6+b15=______.-数学

题目详情

已知Sn,Tn分别是等差数列{an},{bn}的前n项和,且
Sn
Tn
=
2n+1
4n-2
,(n∈N+)则
a10
b3+b18
+
a11
b6+b15
=______.
题型:填空题难度:偏易来源:镇江一模

答案

∵Sn,Tn分别是等差数列{an},{bn}的前n项和,
Sn
Tn
=class="stub"2n+1
4n-2
,(n∈N+),
a10
b3+b18
+
a11
b6+b15
=
a10+a11
b10+b11

=
S20
T20
=class="stub"40+1
80-2
=class="stub"41
78

故答案为:class="stub"41
78

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