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What is the sum of the first 30 terms of this arithmetic sequence?

6, 13, 20, 27, 34, …

User Raj Adroit
by
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1 Answer

2 votes

Answer:

3225

Explanation:

The sum to n terms of an arithmetic sequence is


S_(n) =
(n)/(2) [ 2a + (n - 1)d ]

where a is the first term and d the common difference

here a = 6 and

d = 13 - 6 = 20 - 13 = 7, hence


S_(30) =
(30)/(2)[ (2 × 6) + (29 × 7) ]

= 15(12 + 203) = 15 × 215 = 3225

User SelftaughtMonk
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6.5k points