| $$ \begin{aligned}2x^2-3x+7+2x^2& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}4x^2-3x+7\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{2x^2} -3x+7+ \color{blue}{2x^2} = \color{blue}{4x^2} -3x+7 $$ |