Ответ:
- \(\frac{2}{7}+\frac{3}{8}=\frac{16}{56}+\frac{21}{56}=\frac{37}{56}\).
- \(\frac{5}{6}-\frac{4}{9}=\frac{15}{18}-\frac{8}{18}=\frac{7}{18}\).
- \(3\frac{1}{8}+2\frac{5}{6}=5+\frac{3}{24}+\frac{20}{24}=5\frac{23}{24}\).
- \(5\frac{11}{12}-3\frac{7}{18}=5\frac{33}{36}-3\frac{14}{36}=2\frac{19}{36}\).
