5.412 Выполните действия: a) \(\frac{7}{9} - \frac{5}{12}\) б) \(\frac{5}{6} + \frac{7}{8}\) в) \(\frac{11}{12} - \frac{11}{20}\) г) \(\frac{17}{21} - \frac{8}{15}\) д) \(13 \frac{21}{22} - 11 \frac{3}{55}\) e) \(\frac{40}{40} + \frac{7}{10} - \frac{10}{60}\)

Ответ:

a) \(\frac{7}{9} - \frac{5}{12} = \frac{28}{36} - \frac{15}{36} = \frac{13}{36}\)

б) \(\frac{5}{6} + \frac{7}{8} = \frac{20}{24} + \frac{21}{24} = \frac{41}{24} = 1 \frac{17}{24}\)

в) \(\frac{11}{12} - \frac{11}{20} = \frac{55}{60} - \frac{33}{60} = \frac{22}{60} = \frac{11}{30}\)

г) \(\frac{17}{21} - \frac{8}{15} = \frac{85}{105} - \frac{56}{105} = \frac{29}{105}\)

д) \(13 \frac{21}{22} - 11 \frac{3}{55} = 13 \frac{105}{110} - 11 \frac{6}{110} = 2 \frac{99}{110} = 2 \frac{9}{10}\)

e) \(\frac{40}{40} + \frac{7}{10} - \frac{10}{60} = 1 + \frac{7}{10} - \frac{1}{6} = 1 + \frac{42}{60} - \frac{10}{60} = 1 + \frac{32}{60} = 1 + \frac{8}{15} = 1 \frac{8}{15}\)

Ответ: