S10,S20-S10,330-S20仍成等比,且公比为原公比q的10次方
即S10,24-S10,54成等比
(24-S10)²=54S10
S10²-102S10+576=0
(S10- 96)(S10 -6)=0
S10=6 (S10=96舍去)
S10,S20-S10,330-S20仍成等比,且公比为原公比q的10次方
即S10,24-S10,54成等比
(24-S10)²=54S10
S10²-102S10+576=0
(S10- 96)(S10 -6)=0
S10=6 (S10=96舍去)