Consider the following equation:

$\displaystyle{\left({x}+{2}\right)}{\left({{x}}^{{2}}+{x}-{10}\right)}={{x}}^{{3}}\usepackage{cmbright}\Huge\$ ___ $\displaystyle-{8}{x}-{20}\usepackage{cmbright}\Huge\$

Fill in the blank with the correct term, and be sure to include a positive or negative sign in your answer.

Note: Write exponents by using the ^ key. For example, $\displaystyle{{x}}^{{2}}\usepackage{cmbright}\Huge\$ can be recorded as x^2, and $\displaystyle{5}{{x}}^{{3}}\usepackage{cmbright}\Huge\$ can be recorded as 5x^3.