Question

What is
8
Σ (3n-1) equal to?
n=1

Answer 1

`\displaystyle\sum_(n=1)^(8) (3n-1)\implies \sum_(n=1)^(8)3n~~ - ~~\sum_(n=1)^(8)1\implies 3\sum_(n=1)^(8)n~~ - ~~\sum_(n=1)^(8)1 \\\\\\ 3\left( \cfrac{8(8+1)}{2} \right)~~ - ~~(8)(1)\implies 3(36)-8\implies 108-8\implies \text{\LARGE 100}`