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Select the formula for sum of arithmetic sequence with first term ' a1 and common difference 'd'.
Sn=2an+3S_n=2a_n+3Sn=2an+3
Sn=n2[2a1+and]S_n=\frac{n}{2}[2a_1+a_nd]Sn=2n[2a1+and]
Sn=n2[2a1+(n−1)d]S_n=\frac{n}{2}[2a_1+(n-1)d]Sn=2n[2a1+(n−1)d]
Using the sum of arithmetic sequence formula, calculate the sum of the first 20 terms of the sequence 1, 5, 9, 13,….
495
775
780
Find the sum of 7 terms of an arithmetic sequence whose first and last terms are 10 and 40 respectively.
195
175
156
What is the sum of the first thirty terms of the arithmetic sequence
50, 45, 40, 35, ... ?
-675
453
576
Find the sum of arithmetic sequence -4, -1, 2, 5, ... up to 10 terms.
95
87
56
What is the sum of the first sixteen terms of the arithmetic sequence
1, 5, 9, 13, ... ?
496
567
345
Find the sum of the first 30 terms of the sequence 1, 3, 5, 7, 9 ….
900
Add up the first 10 terms of the arithmetic sequence:
{ 1, 4, 7, 10, 13, ... }
112
145
The first term of an arithmetic sequence is 4 and the tenth term is 67.
What is the common difference?
6
7
8
It is done.