| $$ \begin{aligned}6x-7x^2+4x^2+6& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-3x^2+6x+6\end{aligned} $$ | |
| ① | Combine like terms: $$ 6x \color{blue}{-7x^2} + \color{blue}{4x^2} +6 = \color{blue}{-3x^2} +6x+6 $$ |