$$ \begin{aligned}5x^2y^3(6x^2-7y-1)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}30x^4y^3-35x^2y^4-5x^2y^3\end{aligned} $$ | |
① | Multiply $ \color{blue}{5x^2y^3} $ by $ \left( 6x^2-7y-1\right) $ $$ \color{blue}{5x^2y^3} \cdot \left( 6x^2-7y-1\right) = 30x^4y^3-35x^2y^4-5x^2y^3 $$ |