Вопрос:

1. Вычислите: д) \(\frac{1}{5} - \frac{47}{10}\) е) \(\frac{1}{2} - \frac{9}{10}\) ж) \(\frac{11}{4} - \frac{2}{5}\) 3) \(\frac{1}{4} - \frac{3}{25}\)

Ответ:

Решение:

  1. д) \(\frac{1}{5} - \frac{47}{10} = \frac{1 × 2}{5 × 2} - \frac{47}{10} = \frac{2}{10} - \frac{47}{10} = \frac{2-47}{10} = -\frac{45}{10} = -\frac{9}{2}\)
  2. е) \(\frac{1}{2} - \frac{9}{10} = \frac{1 × 5}{2 × 5} - \frac{9}{10} = \frac{5}{10} - \frac{9}{10} = \frac{5-9}{10} = -\frac{4}{10} = -\frac{2}{5}\)
  3. ж) \(\frac{11}{4} - \frac{2}{5} = \frac{11 × 5}{4 × 5} - \frac{2 × 4}{5 × 4} = \frac{55}{20} - \frac{8}{20} = \frac{55-8}{20} = \frac{47}{20}\)
  4. з) \(\frac{1}{4} - \frac{3}{25} = \frac{1 × 25}{4 × 25} - \frac{3 × 4}{25 × 4} = \frac{25}{100} - \frac{12}{100} = \frac{25-12}{100} = \frac{13}{100}\)

Ответ: д) -\(\frac{9}{2}\), е) -\(\frac{2}{5}\), ж) \(\frac{47}{20}\), з) \(\frac{13}{100}\).