a1+a2=39,a3+a4=33,则a5+a6=?
a1+a2=39,a3+a4=33,则a5+a6=?
等差数列an中a1+a2=39 a3+a4=33则a5+a6的值
A1+A3+A5+A7=4,求A2+A4+A6
等差数列an中a1+a2=39 a3+a4=33求a5+a6
a2*a6=4,求a1*a2*a3*a4*a5*a6*a7
等比数列 a1*a4*a7=39 a2*a5*a8=13求a3*a6*a9
等比数列{an}中,已知a1+a2=20,a3+a4=40,则a5+a6=
等比数列中,已知a1+a2=20,a3+a4=40,则a5+a6=
(1)a1+a2+a3=30 a4+a5+a6=80 则a7+a8+a9=?
等比数列an中,a1+a2+a3+a4+a5=31,a2+a3+a4+a5+a6=62,则通项公式为?
a1=8,a7=5832,a1/a2=a2/a3=a3/a4=a4/a5=a5/a6=a6/a7,求a5的值
已知集合A={a1,a2,a3,a4,a5,a6,a7},A并上B={a1,a2,a3,a4,a5,a6,a7,.,a1