1 . 已知
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3141867ee39d13c01afb6b169a587761.png)
___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f08f11459b4473bbea395aab5813662.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3141867ee39d13c01afb6b169a587761.png)
您最近一年使用:0次
2 . 各项均为正数的等比数列
满足
则数列
的前4项和为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d21aeb88b78563bbd1444802e4a8ce8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
A.20 | B.100 | C.110 | D.120 |
您最近一年使用:0次
A.20 | B.100 | C.110 | D.120 |