$$ \begin{aligned}x^2+x^4+x^6+x^6+x^8& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}x^8+2x^6+x^4+x^2\end{aligned} $$ | |
① | Combine like terms: $$ x^2+x^4+ \color{blue}{x^6} + \color{blue}{x^6} +x^8 = x^8+ \color{blue}{2x^6} +x^4+x^2 $$ |