来自桂现才的问题
已知公差大于零的等差数列｛an｝的前n项和为Sn,且满足:a3*a4=117,a2+a5=221.等差数列{an}2.若数列{bn}是等差数列,bn=Sn/(n+c),求非零常数c；3.若2中的{bn}的前n项和为Tn,求证：2Tn-3bn-1＞64bn/﹛(n+9)*bn+1﹜
已知公差大于零的等差数列｛an｝的前n项和为Sn,且满足:a3*a4=117,a2+a5=22
1.等差数列{an}
2.若数列{bn}是等差数列,bn=Sn/(n+c),求非零常数c；
3.若2中的{bn}的前n项和为Tn,求证：2Tn-3bn-1＞64bn/﹛(n+9)*bn+1﹜
