Correct. You can use the distributive property (in reverse) to write $\displaystyle{{x}}^{{2}}+{7}{x}\usepackage{cmbright}\Huge\$ as $\displaystyle{x}{\left({x}+{7}\right)}\usepackage{cmbright}\Huge\$ and to write $\displaystyle-{4}{x}-{28}\usepackage{cmbright}\Huge\$ as $\displaystyle-{4}{\left({x}+{7}\right)}\usepackage{cmbright}\Huge\$ . This gives $\displaystyle{x}{\left({x}+{7}\right)}+{\left(-{4}\right)}{\left({x}+{7}\right)}\usepackage{cmbright}\Huge\$ . Notice that $\displaystyle{\left({x}+{7}\right)}\usepackage{cmbright}\Huge\$ appears twice. Use the distributive property again to factor out the $\displaystyle{x}+{7}\usepackage{cmbright}\Huge\$ to get $\displaystyle{\left({x}+{7}\right)}{\left({x}-{4}\right)}\usepackage{cmbright}\Huge\$ .