等比数列
的前n项和
(a为常数),
,则数列
的前n项和为_____________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0231b0cfb591e6bce0eea64bb5863649.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b4e5bb55dc85150de816e2d475e94aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
更新时间:2018-11-17 09:21:56
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解题方法
【推荐2】已知数列
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解题方法
【推荐1】已知正项等比数列
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b422a39788aeb7ad87dfc81ec9e96a6.png)
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