Correct. This polynomial is in the special form $\displaystyle{{a}}^{{2}}-{2}{a}{b}+{{b}}^{{2}}\usepackage{cmbright}\Huge\$ , so it will be factored as $\displaystyle{{\left({a}-{b}\right)}}^{{2}}\usepackage{cmbright}\Huge\$ . The square root of $\displaystyle{36}{{x}}^{{2}}={6}{x}\usepackage{cmbright}\Huge\$ , and the square root of 49 is 7. $\displaystyle{36}{{x}}^{{2}}-{84}{x}+{49}={\left({6}{x}-{7}\right)}{\left({6}{x}-{7}\right)}\usepackage{cmbright}\Huge\$ .