You may have started with the correct first step:

$\displaystyle{f{{\left({x}\right)}}}\cdot{g{{\left({x}\right)}}}={\left({6}{x}+{2}\right)}{\left(-{9}{x}-{5}\right)}\usepackage{cmbright}\Huge\$

However, after using FOIL, you combined the terms incorrectly. You might have thought that combining two negative terms would give you a positive, but you were confusing addition and multiplication.