| $$ \begin{aligned}2+19a+17& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}19a+19\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{2} +19a+ \color{blue}{17} = 19a+ \color{blue}{19} $$ |