Question

What is the sum of the series?
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Answer 1

The sum of the series is 30

Answer 2

30

Explanation:

Substitute j = 1, 2, 3, 4, 5 into 2j and sum the terms, that is

2(1) + 2(2) + 2(3) + 2(4) + 2(5)

= 2 + 4 + 6 + 8 + 10

= 30