We can multiply polynomials by using a GRID METHOD
Write one of the polynomials across the top and the other down the left side.
$$ \begin{darray}{|c|c|c|c|}\hline & \color{blue}{n^2} & \color{blue}{n} & \color{blue}{1} \\ \hline \color{blue}{2n} & & & \\ \hline \color{blue}{-2} & & & \\ \hline \end{darray} $$Fill in each empty box by multiplying the intersecting terms.
$$ \begin{darray}{|c|c|c|c|}\hline & \color{blue}{n^2} & \color{blue}{n} & \color{blue}{1} \\ \hline \color{blue}{2n} & \color{orangered}{2n^3} & \color{orangered}{2n^2} & \color{orangered}{2n} \\ \hline \color{blue}{-2} & \color{orangered}{-2n^2} & \color{orangered}{-2n} & \color{orangered}{-2} \\ \hline \end{darray} $$Combine like terms:
$$ 2n^3 + 2n^2-2n^2 + 2n-2n-2 = \\ 2n^3-2 $$