\[\boxed{\text{5.504.}}\]
\[\textbf{а)}\ \frac{1^{\backslash 7}}{4} + \frac{1^{\backslash 4}}{7} = \frac{7}{28} + \frac{4}{28} = \frac{11}{28}\]
\[\textbf{б)}\ \frac{1^{\backslash 5}}{4} - \frac{1^{\backslash 4}}{5} = \frac{5}{20} - \frac{4}{20} = \frac{1}{20}\]
\[\textbf{в)}\ \frac{1}{2} - \frac{3}{8} = \frac{4}{8} - \frac{3}{8} = \frac{1}{8}\]
\[\textbf{г)}\ \frac{1^{\backslash 5}}{3} - \frac{1^{\backslash 3}}{5} = \frac{5}{15} - \frac{3}{15} = \frac{2}{15}\]
\[\textbf{д)}\ 4 + \frac{4}{7} = 4\frac{4}{7}\]
\[\textbf{е)}\ \frac{3}{4} + \frac{5}{6} = \frac{9}{12} + \frac{10}{12} = \frac{19}{12} = 1\frac{7}{12}\ \]