Algebra 1: Common Core (15th Edition)

$12z^{4}+4z^{3}+3z^{2}+z$.
Make a table of products. $\begin{array}{rll} & z & +3z^{2}\\ \hline 4z^{2}| & 4z^{3} & 12z^{4}\\ 1 |& z & 3z^{2} \end{array}$ Answer: $12z^{4}+4z^{3}+3z^{2}+z$.