$$ \begin{aligned}(-i)(-2x)^2& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}(-i)\cdot4x^2 \xlongequal{ } \\[1 em] & \xlongequal{ }-4ix^2\end{aligned} $$ | |
① | $$ \left( -2x \right)^2 = (-2)^2x^2 = 4x^2 $$ |