1 . 记等差数列
的前
项和为
,若
,
,则
( )
![](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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c569a4e466ce282b2283b460971d7bf8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0073ad686435c906d947d714be161205.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b11e2bf8d65c24fc845446a32d881bd4.png)
A.64 | B.80 | C.96 | D.120 |
您最近一年使用:0次
2024-03-06更新
|
2203次组卷
|
8卷引用:湖北省云学名校联盟2023-2024学年高二下学期3月联考数学试卷
2 . 参考《九章算术》中“竹九节”问题,提出:一根9节的竹子,自上而下各节的容积成等差数列,最上面3节的容积共3升,最下面3节的容积共6升,则第5节的容积为__________ 升.
您最近一年使用:0次