Correct. All of these values are excluded from the domain of the expression since each of them results in division by 0. Notice that values for x that result in a numerator or a denominator of 0 for the expression $\displaystyle\frac{{{{x}}^{{2}}+{8}{x}+{16}}}{{{{x}}^{{2}}+{5}{x}}}\usepackage{cmbright}\Huge\$ are excluded from the domain.