Which of the following represents the sum of the series? cap s sub n is equal to the sum from k is equal to 1 to 7 of open bracket 1 plus open paren k minus 1 close paren close bracket

Simplify the term inside the brackets: 1 + (k − 1) = k. As k goes from 1 to 7, the terms are 1, 2, 3, 4, 5, 6, and 7. So the series is the sum of the seven numbers beginning with 1.

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