Вопрос:

Вычислите: а) 5/7 + 1/7; б) 3/5 + 1/6; в) 7/15 + 1/3; г) 1/20 + 2/15; д) 5/8 − 2/8; е) 8/9 − 1/2; ж) 3/4 − 5/16; з) 7/22 − 2/33.

Ответ:

  1. \(\frac{5}{7}+\frac{1}{7}=\frac{6}{7}\).
  2. \(\frac{3}{5}+\frac{1}{6}=\frac{18}{30}+\frac{5}{30}=\frac{23}{30}\).
  3. \(\frac{7}{15}+\frac{1}{3}=\frac{7}{15}+\frac{5}{15}=\frac{12}{15}=\frac{4}{5}\).
  4. \(\frac{1}{20}+\frac{2}{15}=\frac{3}{60}+\frac{8}{60}=\frac{11}{60}\).
  5. \(\frac{5}{8}-\frac{2}{8}=\frac{3}{8}\).
  6. \(\frac{8}{9}-\frac{1}{2}=\frac{16}{18}-\frac{9}{18}=\frac{7}{18}\).
  7. \(\frac{3}{4}-\frac{5}{16}=\frac{12}{16}-\frac{5}{16}=\frac{7}{16}\).
  8. \(\frac{7}{22}-\frac{2}{33}=\frac{21}{66}-\frac{4}{66}=\frac{17}{66}\).

Ответ: а) \(\frac{6}{7}\); б) \(\frac{23}{30}\); в) \(\frac{4}{5}\); г) \(\frac{11}{60}\); д) \(\frac{3}{8}\); е) \(\frac{7}{18}\); ж) \(\frac{7}{16}\); з) \(\frac{17}{66}\).