The domain will exclude values for which the value of the denominator is 0. In this expression $\displaystyle{\left({x}-{3}\right)}{\left({x}-{2}\right)}\usepackage{cmbright}\Huge\$ is the denominator, and the value of the denominator will be 0 when $\displaystyle{x}={3}\usepackage{cmbright}\Huge\$ and when $\displaystyle{x}={2}\usepackage{cmbright}\Huge\$ . These values are excluded from the domain.