Вопрос:

Вычислите: 27/76 − 0; 9/20 + 5/8; 2/7 + 13/28; 5/13 − 14/39; 5/8 − 2/7.

Ответ:

  1. \(\frac{27}{76}-0=\frac{27}{76}\).
  2. \(\frac{9}{20}+\frac{5}{8}=\frac{18}{40}+\frac{25}{40}=\frac{43}{40}=1\frac{3}{40}\).
  3. \(\frac{2}{7}+\frac{13}{28}=\frac{8}{28}+\frac{13}{28}=\frac{21}{28}=\frac{3}{4}\).
  4. \(\frac{5}{13}-\frac{14}{39}=\frac{15}{39}-\frac{14}{39}=\frac{1}{39}\).
  5. \(\frac{5}{8}-\frac{2}{7}=\frac{35}{56}-\frac{16}{56}=\frac{19}{56}\).

Ответ: \(\frac{27}{76};\ 1\frac{3}{40};\ \frac{3}{4};\ \frac{1}{39};\ \frac{19}{56}\).