| $$ \begin{aligned}-8i-8i& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-16i\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{-8i} \color{blue}{-8i} = \color{blue}{-16i} $$ |