若等比数列{an}满足A2+A4=20,A3+A5=40,则Q=?前n项Sn?
若等比数列{an}满足A2+A4=20,A3+A5=40,则Q=?前n项Sn?
若等比数列an满足a2十a4=20、a3十a5=40则公比q=?前n项和sn=
若等比数列{an}满足a2+a4=20,a3+a5=40,则公比q=?;前n项Sn=?
)若等比数列{an}满足a2+a4=20,a3+a5=40,则公比q=________;前n项和Sn=________.
等比数列{an}满足a2+a4=20,a3+a5=40,则公比q=( )
若等比数列an满足a2加a4等于20.a3加a5等于40.则公比q等于?前n项和Sn等于?
若等比数列{an}满足a2+a4=20,a3+a5=40,则a3=______.
已知等差数列{an}满足:a3+a4=16,a4+a5=20,{an}的前n项和为Sn
已知等比数列{an}中,公比q∈R,且a1+a2+a3=9,a4+a5+a6=-3,Sn为数列{an}的前n项和,则li
等差数列{An}的前n项和为Sn,且满足A3*A4=117,A2+A5=22 求通项An ;若数列{Bn}是等差数列,且
数列{an}的前n项和为sn=n2+3n+1,则a1+a2+a3+a4+a5
已知等比数列an满足:a1+a2+a3+a4+a5=3,则a1-a2+a3-a4+a5的值是