设数列{bn}的前n项和为Sn,且bn=2-2Sn,数列{an}为等差数列,且a5=14,a7=20

设数列{bn}的前n项和为sn,且bn=2-2sn;数列{an}为等差数列,且a5=14,a7=20求 设数列{bn}的前n项和为Sn,且bn=2-2Sn,数列{an}为等差数列,且a5=14,a7=20 设数列｛Bn｝的前n项和为Sn,且Bn=2-2Sn;数列｛An｝为等差数列,且A5=14,A7=20. 设数列{bn}的前n项和为Sn,且bn=2-2s.数列{an}为等差数列,且a5=14,a7=20. 设数列{bn}的前n项和为Sn,且bn=2-2Sn,数列{an}为等差数列,且a5=14,a7=20 （1）求数列{bn 设数列Bn的前n项和为Sn.且Bn=2-2Sn,数列An为等差数列.a5=14 a7=20,求Bn的通项公式 设数列Bn的前n项和为Sn,且Bn=2-2Sn.数列An为等差数列,且A5=10,A7=14.(1)求数列An、{bn} 设数列bn的前n项和为Sn.且bn=2-2Sn.数列an为等差数列,a5=14.a7=20.求数列bn通项公式.2,若c 设数列{bn}的前n项和为Sn,且bn＝2—2Sn;数列{an}为等差数列,且a5＝14,a7＝20 若Cn＝An·Bn 设数列｛bn｝的前n项和为sn,且bn＝1－2sn；数列｛an｝为等差数列,且a5＝14,a7＝20.求数列｛bn｝的通 已知数列{an}为等差数列，a3=5，a7=13，数列{bn}的前n项和为Sn，且有Sn=2bn-1 设数列{bn}的前n项和为Sn,且Sn=1-bn/2;数列{an}为等差数列,且a6=17,a8=23,