Correct. Factor out 4 and set the equation to zero: $\displaystyle{{x}}^{{2}}+{6}{x}-{8}={0}\usepackage{cmbright}\Huge\$ . Completing the square you find that $\displaystyle{{x}}^{{2}}+{6}{x}+{9}={17}\usepackage{cmbright}\Huge\$ , which can be rewritten as $\displaystyle{{\left({x}+{3}\right)}}^{{2}}={17}\usepackage{cmbright}\Huge\$ , so the roots are $\displaystyle{x}=-{3}+\sqrt{{{17}}}\usepackage{cmbright}\Huge\$ and $\displaystyle{x}=-{3}-\sqrt{{{17}}}\usepackage{cmbright}\Huge\$ .