## Precalculus (6th Edition) Blitzer

The first term of $\sum\limits_{i=1}^{20}{\left( 6i-\text{ }4 \right)}$ is 2 and the last term is 116.
To find the first term, we will substitute $i=1$ in the given equation \begin{align} & 6i-4=6\left( 1 \right)-4 \\ & =6-4 \\ & =2 \end{align} To find the last term, we will substitute $i=20$ in the given equation \begin{align} & 6i-4=6\left( 20 \right)-4 \\ & =120-4 \\ & =116 \end{align}