Correct.

$\displaystyle{g{{\left({x}\right)}}}-{f{{\left({x}\right)}}}={6}{{x}}^{{2}}-{3}{x}+{7}-{\left({6}{{x}}^{{2}}-{5}{x}+{7}\right)}={6}{{x}}^{{2}}-{3}{x}+{7}-{6}{{x}}^{{2}}+{5}{x}-{7}\usepackage{cmbright}\Huge\$

$\displaystyle={6}{{x}}^{{2}}-{6}{{x}}^{{2}}-{3}{x}+{5}{x}+{7}-{7}={2}{x}\usepackage{cmbright}\Huge\$ . The one term is $\displaystyle{2}{x}\usepackage{cmbright}\Huge\$ .