配套习题- 等差数列前n项和公式 -【青果学院】

1/5单选题

难度：

1.已知等差数列

中，

，

，则该数列前9项和

等于

A	55
B	45
C	35
D	25

正确答案：Qg==

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

2/5单选题

难度：

2.已知等差数列

中，

，则该数列前9项和

等于

A	18
B	27
C	36
D	45

正确答案：Qw==

4oi1PGltZyB3aWR0aD0xMzQgaGVpZ2h0PTIxIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMkYvNjAvckJBQ0oxU2pvRUdna1FwRkFBQUNQM29TRERnMDkxLnBuZyI+77yM5Luj5YWlPGltZyB3aWR0aD0xODAgaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvNjMvMjYvckJBQ0UxU2pvRUhTR2NZaEFBQURScExDckpVNDczLnBuZyI+5omA5Lul6YCJQy4=

3/5单选题

难度：

3.设

是等差数列

的前

项和，已知

,则

A	13
B	35
C	49
D	63

正确答案：RA==

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

4/5单选题

难度：

4.设

是等差数列

的前

项和，若

,则

A	8
B	7
C	6
D	5

正确答案：RA==

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

5/5单选题

难度：

5.在等差数列

中，已知

A	40
B	42
C	43
D	45

正确答案：Qg==

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