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4 votes
Find the sum of the first 200 terms of the arithmetic sequence:

4,7,10,13,...

1 Answer

3 votes

Answer:

60500

Explanation:

The sum to n terms of an arithmetic sequence is


S_(n) =
(n)/(2) [ 2a₁ + (n - 1)d ]

where a₁ is the first term and d the common difference

Here a₁ = 4 and d = 7 - 4 = 3, thus


S_(200) =
(200)/(2) [ (2 × 4) + (199 × 3) ]

= 100(8 + 597)

= 100 × 605

= 60500