Question

11Evaluate Σ(32 - 8).=1Ο Α. 355Ο Β. 1,510Ο C. 418Ο D. 1,430

Answer 1

given:

`\sum ^(11)_(i=1)\: \mleft(3i^2-8\mright)`
`\begin{gathered} \sum ^(11)_(i=1)3i^2-8 \\ =\sum ^(11)_(i=1)3i^2-\sum ^(11)_(i=1)8 \\ \sum ^(11)_(i=1)3i^2=1518 \\ \sum ^(11)_(i=1)8=88 \\ \sum ^(11)_(i=1)3i^2-\sum ^(11)_(i=1)8=1518-88 \\ =1430 \end{gathered}`

The answer is option D) 1430.