Correct. You can check your work by multiplying $\displaystyle{\left({x}+{4}\right)}{\left({x}+{4}\right)}\usepackage{cmbright}\Huge\$ , or $\displaystyle{x}{\left({x}+{4}\right)}+{4}{\left({x}+{4}\right)}\usepackage{cmbright}\Huge\$ , which equals $\displaystyle{{x}}^{{2}}+{8}{x}+{16}\usepackage{cmbright}\Huge\$ .