$$ \begin{aligned}3x^2y(-2x^3y^4+3x^2y+2x-8y)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-6x^5y^5+9x^4y^2+6x^3y-24x^2y^2\end{aligned} $$ | |
① | Multiply $ \color{blue}{3x^2y} $ by $ \left( -2x^3y^4+3x^2y+2x-8y\right) $ $$ \color{blue}{3x^2y} \cdot \left( -2x^3y^4+3x^2y+2x-8y\right) = -6x^5y^5+9x^4y^2+6x^3y-24x^2y^2 $$ |