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Find S or the sum for the given arithmetic series. a1 = –84, d = –2, n = 22

2 Answers

4 votes

Answer:

S₂₂ = - 2310

Explanation:

the sum to n terms of an arithmetic series is


S_(n) =
(n)/(2) [ 2a₁ + (n - 1)d ]

given a₁ = - 84, d = - 2, n = 22 , then

S₂₂ =
(22)/(2) [ (2 × - 84) + (21 × - 2) ]

= 11 (- 168 - 42)

= 11 × - 210

= - 2310

User Iakov Nakhimovski
by
8.5k points
3 votes

consider the other one I used the wrong method.

User Moxspoy
by
8.9k points

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