| $$ \begin{aligned}(-3ac^3)^3& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-27a^3c^9\end{aligned} $$ | |
| ① | $$ \left( -3ac^3 \right)^3 = (-3)^3a^3 \left( c^3 \right)^3 = -27a^3c^9 $$ |