Evaluate: .

Answer and explanation

Correct answer: B.

  1. Step 1: Split the sum: , where .
  2. Step 2: .
Answer
.
Why not the others: : the constant term b was not summed n times. : the sum of k was taken as n instead of n(n+1)/2. : b was attached to the wrong part of the sum.

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Evaluate: sum k=1 8 (4k - 2). | South Africa Matric