$$ \begin{aligned}a^2-2a+5a^3+1-10a& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}5a^3+a^2-12a+1\end{aligned} $$ | |
① | Combine like terms: $$ a^2 \color{blue}{-2a} +5a^3+1 \color{blue}{-10a} = 5a^3+a^2 \color{blue}{-12a} +1 $$ |