Consider the following equation:

$\displaystyle{4}{{x}}^{{2}}{\left({5}{{x}}^{{3}}+{4}\right)}=\usepackage{cmbright}\Huge\$ ____ $\displaystyle+{16}{{x}}^{{2}}\usepackage{cmbright}\Huge\$

Fill in the blank with the correct term.

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.