Incorrect. Rewrite in standard form by adding 49 to both sides: $\displaystyle{{x}}^{{2}}-{14}{x}+{49}={0}\usepackage{cmbright}\Huge\$

Then use the Quadratic Formula, $\displaystyle{x}=\frac{{-{b}\pm\sqrt{{{{b}}^{{2}}-{4}{a}{c}}}}}{{{2}{a}}}\usepackage{cmbright}\Huge\$ , with $\displaystyle{a}={1},{b}=-{14}\usepackage{cmbright}\Huge\$ , and $\displaystyle{c}={49}\usepackage{cmbright}\Huge\$ . The correct answer is 7.