Find the sum of the first 20 terms of the sequence -7-3, 1, ......
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Correct Answer: Option A
Explanation:
d = -3 - (-7) = 4
S\(_{20}\) = \(\frac{20}{2}\){2(-7) + (20 - 1) 4}
= 10(- 14 + 76)
= 620
d = -3 - (-7) = 4
S\(_{20}\) = \(\frac{20}{2}\){2(-7) + (20 - 1) 4}
= 10(- 14 + 76)
= 620