数列{An}和{Bn}是等差数列
由等差数列的性质:a15+a1=2a8
同理b15+b1=2b8
{an}的前15项和为S15=(a1+a15)*15/2,
{bn}的前15项和为T15=(b1+b15)*15/2,
S15/T15=a8/b8=(7*15+2)/(15+3)=107/18
数列{An}和{Bn}是等差数列
由等差数列的性质:a15+a1=2a8
同理b15+b1=2b8
{an}的前15项和为S15=(a1+a15)*15/2,
{bn}的前15项和为T15=(b1+b15)*15/2,
S15/T15=a8/b8=(7*15+2)/(15+3)=107/18