Incorrect. Since dividing by 0 is undefined, x cannot be 0, since $\displaystyle\frac{{{x}+{1}}}{{9}}\div\frac{{x}}{{3}}=\frac{{1}}{{9}}\div\frac{{0}}{{3}}=\frac{{1}}{{9}}\div{0}\usepackage{cmbright}\Huge\$ . The domain of the expression includes all values of x except for $\displaystyle{x}={0}\usepackage{cmbright}\Huge\$ .