Correct. Values of $\displaystyle{x}=-{6}\usepackage{cmbright}\Huge\$ , $\displaystyle{x}=-{2}\usepackage{cmbright}\Huge\$ , or $\displaystyle{x}={5}\usepackage{cmbright}\Huge\$ would cause division by 0. Since division by 0 is undefined, these values must be excluded from the domain of the expression.