We can multiply polynomials by using a GRID METHOD
Write one of the polynomials across the top and the other down the left side.
$$ \begin{darray}{|c|c|c|c|}\hline & \color{blue}{2x^2} & \color{blue}{-x} & \color{blue}{-3} \\ \hline \color{blue}{x} & & & \\ \hline \color{blue}{-2} & & & \\ \hline \end{darray} $$Fill in each empty box by multiplying the intersecting terms.
$$ \begin{darray}{|c|c|c|c|}\hline & \color{blue}{2x^2} & \color{blue}{-x} & \color{blue}{-3} \\ \hline \color{blue}{x} & \color{orangered}{2x^3} & \color{orangered}{-x^2} & \color{orangered}{-3x} \\ \hline \color{blue}{-2} & \color{orangered}{-4x^2} & \color{orangered}{2x} & \color{orangered}{6} \\ \hline \end{darray} $$Combine like terms:
$$ 2x^3-x^2-4x^2-3x + 2x + 6 = \\ 2x^3-5x^2-x+6 $$