\[\boxed{\text{5.395.}}\]
\[\textbf{а)}\ \frac{7}{14} < \frac{25}{42}\]
\[\frac{7}{14} = \frac{21}{42} < \frac{25}{42}\text{.\ }\]
\[\textbf{б)}\ \frac{10}{12} > \frac{11}{14}\]
\[\frac{10}{12} = \frac{5}{6} = \frac{35}{42};\ \ \frac{11}{14} = \frac{33}{42};\]
\[\frac{35}{42} > \frac{33}{42}\text{.\ \ }\]