Решебник по математике 5 класс Виленкин Часть 1, 2 Часть 2. Параграф 5. Обыкновенные дроби Задание 419

\[\boxed{\text{5.419.}}\]

\[c = 1:\]

\[\frac{c}{10} + \frac{c}{25} = \frac{1}{10} + \frac{1}{25} = \frac{5}{50} + \frac{2}{50} =\]

\[= \frac{7}{50}\text{.\ }\]

\[c = 3:\]

\[\frac{c}{10} + \frac{c}{25} = \frac{3}{10} + \frac{3}{25} = \frac{15}{50} + \frac{6}{50} =\]

\[= \frac{21}{50}\text{.\ }\]

\[c = 7:\ \]

\[\frac{c}{10} + \frac{c}{25} = \frac{7}{10} + \frac{7}{25} = \frac{35}{50} + \frac{14}{50} =\]

\[= \frac{49}{50}\text{.\ }\]

\[c = 9:\]

\[\frac{c}{10} + \frac{c}{25} = \frac{9}{10} + \frac{9}{25} = \frac{45}{50} + \frac{18}{50} =\]

\[= \frac{63}{50} = 1\frac{13}{50}\text{.\ \ }\]