等差数列｛an｝满足a1＋a2＋a3＋…a101＝0,则有

等差数列｛an｝满足a1＋a2＋a3＋…a101＝0,则有 已知a1＋a5＝8,a2·a3＝2,求通项公式an等差数列 等差数列中a1.a2.a3.a4.a1＋a2＝a3+a4? 已知等差数列｛an｝满足a1+a2+a3+……+a99＝0则( ) A.a1+a99>0 B.a已知等差数列｛an｝满足a1+a2+a3+……+a99＝0则( )A.a1+a99>0 B.a1+a99 等差数列[an]中,若a1＋a3＋a5=-1则a1＋a2＋a4＋a5= 已知数列{an}满足a1＝1,an=a1＋1/2a2＋1/3a3+…＋1/(n－1)an 等差数列an公差不等于0且a1,a3,a9成等比数列,求（a1＋a3＋a9）除（a2＋a4＋a10） 已知数列{an}和{bn}满足关系:bn=(a1+a2+a3+…+an)/n,(n∈N*).若{bn}是等差数列,求证{an}为等差数列 已知an为等差数列,a1＋a3＋a5＝105,a2＋a4＋a6＝99,求a20 等差数列an中 a1＋a4＝39 a2＋a5＝35 则a3＋a6＝ 已知等差数列{an}满足a1+a2+a3+……+a101=0,则有（）A.a1+a101>0 B.a2+a100 等差数列an满足a1+a2+...+a101=303 则a3+a99= 已知等差数列{an}满足a1+a2+a3+...+a11=0,则有A、a1+a11>0B、a2+a10 数列{an}{bn}满足bn=a1+2a2+3a3+…+nan/(1+2+3+…+n),若数列{an}为等差数列,求证；{bn}为等差数列. 等差数列an,若a1+a2+a3.+a1000 B、a3+a98 设数列{an}满足：a1+a2/2+a3/3+a4/4……+an/n=An+B,其中A、B为常数.数列{an}是否为等差数列? an是等比数列,a1＋a2＋a3＝7,a1*a2*a3＝8,求an? 已知数列{an}为等比数列a1＋a2+a3=21 a1×a2×a3＝216 求an