WeBWorK Standalone Renderer

Use a vertical format to add the polynomials.

$\begin{alignedat}{6} 12x^{6}&{}-{}&17x^{5}&{}+{}&16x^{4}&&&&&{}-{}&2&\\ &&&&-10x^{4}&{}+{}&5x^{3}&{}-{}&7x^{2}&{}+{}&9\\ \hline \end{alignedat}$