| $$ \begin{aligned}4h+3+3h+1& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}7h+4\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{4h} + \color{red}{3} + \color{blue}{3h} + \color{red}{1} = \color{blue}{7h} + \color{red}{4} $$ |