Вопрос:

7. Вычислите: 8) 10 − 9\(\frac{3}{10}\); 9) 5\(\frac{2}{7}\) − 2\(\frac{3}{7}\); 10) 14\(\frac{6}{20}\) − 8\(\frac{12}{20}\); 11) 8\(\frac{3}{14}\) − 5\(\frac{9}{14}\); 12) 7\(\frac{10}{21}\) − 4\(\frac{15}{21}\); 13) 14\(\frac{8}{31}\) − 6\(\frac{18}{31}\).

Ответ:

  1. \(10-9\frac{3}{10}=9\frac{10}{10}-9\frac{3}{10}=\frac{7}{10}\).
  2. \(5\frac{2}{7}-2\frac{3}{7}=4\frac{9}{7}-2\frac{3}{7}=2\frac{6}{7}\).
  3. \(14\frac{6}{20}-8\frac{12}{20}=13\frac{26}{20}-8\frac{12}{20}=5\frac{14}{20}=5\frac{7}{10}\).
  4. \(8\frac{3}{14}-5\frac{9}{14}=7\frac{17}{14}-5\frac{9}{14}=2\frac{8}{14}=2\frac{4}{7}\).
  5. \(7\frac{10}{21}-4\frac{15}{21}=6\frac{31}{21}-4\frac{15}{21}=2\frac{16}{21}\).
  6. \(14\frac{8}{31}-6\frac{18}{31}=13\frac{39}{31}-6\frac{18}{31}=7\frac{21}{31}\).

Ответ: 8) \(\frac{7}{10}\); 9) \(2\frac{6}{7}\); 10) \(5\frac{7}{10}\); 11) \(2\frac{4}{7}\); 12) \(2\frac{16}{21}\); 13) \(7\frac{21}{31}\).