Решебник по математике 5 класс Виленкин Часть 1, 2 Часть 2. Задачи на повторение 15

\[\boxed{\text{П.15.}}\]

\[\textbf{а)}\ \frac{7}{8} < \frac{8}{9}\]

\[\frac{7}{8} = \frac{63}{72};\ \ \ \ \frac{8}{9} = \frac{64}{72}\text{.\ }\]

\[\frac{9}{11} < \frac{15}{17}\]

\[\frac{9}{11} = \frac{153}{187};\ \ \ \ \frac{15}{17} = \frac{165}{187}\text{.\ }\]

\[\textbf{б)}\ \frac{13}{14} = \frac{26}{28} > \frac{25}{28}\]

\[\frac{13}{15} > \frac{21}{25}\]

\[\frac{13}{15} = \frac{65}{75};\ \ \ \frac{21}{25} = \frac{63}{25}\text{.\ \ \ \ }\]