a1=0,a2=600.a3=1800,a4=3600,a5=6000,a6=10800,请问a7=多少?
A1+A3+A5+A7=4,求A2+A4+A6
a2*a6=4,求a1*a2*a3*a4*a5*a6*a7
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
已知一列数a1,a2,a3,a4,a5,a6,a7,且a1=1,a7=729,a1/a2=a2/a3=a3/a4=a4/
已知集合A={a1,a2,a3,a4,a5,a6,a7},A∪B={a1,a2,a3,a4,a5,a6,a7.,a100
等比数列,a1+a2+a3=6,a2+a3+a4=3,求a3+a4+a5+a6+a7+a8=?
设数列ai>0.且a1+a2+a3+a4+a5+a6+a7+a8+a9+a10=30,a1*a2*a3*a4*a5*a6
a1+a2+a3=30.a4+a5+a6=80.a7+a8+a9=?
(1)a1+a2+a3=30 a4+a5+a6=80 则a7+a8+a9=?
等比数列,a1+a4+a7=23,a2+a5+a8=29,a3+a6+a9=
等比数列 a1*a4*a7=39 a2*a5*a8=13求a3*a6*a9