| $$ \begin{aligned}a-38a-24& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-37a-24\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{a} \color{blue}{-38a} -24 = \color{blue}{-37a} -24 $$ |