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