$$ \begin{aligned}6(x^2+6)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}6x^2+36\end{aligned} $$ | |
① | Multiply $ \color{blue}{6} $ by $ \left( x^2+6\right) $ $$ \color{blue}{6} \cdot \left( x^2+6\right) = 6x^2+36 $$ |