$$ \begin{aligned}2y^2(y^5-4y)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}2y^7-8y^3\end{aligned} $$ | |
① | Multiply $ \color{blue}{2y^2} $ by $ \left( y^5-4y\right) $ $$ \color{blue}{2y^2} \cdot \left( y^5-4y\right) = 2y^7-8y^3 $$ |