$$ \begin{aligned}5x(x^2-2)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}5x^3-10x\end{aligned} $$ | |
① | Multiply $ \color{blue}{5x} $ by $ \left( x^2-2\right) $ $$ \color{blue}{5x} \cdot \left( x^2-2\right) = 5x^3-10x $$ |