You probably factored correctly to get $\displaystyle{9}{x}{\left({x}+{3}\right)}={0}\usepackage{cmbright}\Huge\$ , but then solved $\displaystyle{9}{x}={0}\usepackage{cmbright}\Huge\$ incorrectly. To isolate the variable, you must divide both sides by 9. The correct answer is $\displaystyle{x}={0}\usepackage{cmbright}\Huge\$ or $\displaystyle{x}=-{3}\usepackage{cmbright}\Huge\$ .