We can multiply polynomials by using a GRID METHOD
Write one of the polynomials across the top and the other down the left side.
$$ \begin{darray}{|c|c|c|c|}\hline & \color{blue}{4x^2} & \color{blue}{-2x} & \color{blue}{-2} \\ \hline \color{blue}{4x} & & & \\ \hline \color{blue}{6} & & & \\ \hline \end{darray} $$Fill in each empty box by multiplying the intersecting terms.
$$ \begin{darray}{|c|c|c|c|}\hline & \color{blue}{4x^2} & \color{blue}{-2x} & \color{blue}{-2} \\ \hline \color{blue}{4x} & \color{orangered}{16x^3} & \color{orangered}{-8x^2} & \color{orangered}{-8x} \\ \hline \color{blue}{6} & \color{orangered}{24x^2} & \color{orangered}{-12x} & \color{orangered}{-12} \\ \hline \end{darray} $$Combine like terms:
$$ 16x^3-8x^2 + 24x^2-8x-12x-12 = \\ 16x^3+16x^2-20x-12 $$