Ответ:

  1. \(\frac{5}{6}+\frac{2}{7}=\frac{35}{42}+\frac{12}{42}=\frac{47}{42}=1\frac{5}{42}\).
  2. \(\frac{11}{25}-\frac{3}{10}=\frac{22}{50}-\frac{15}{50}=\frac{7}{50}\).
  3. \(\frac{15}{16}-\frac{3}{4}=\frac{15}{16}-\frac{12}{16}=\frac{3}{16}\).
  4. \(\frac{3}{20}+\frac{7}{15}=\frac{9}{60}+\frac{28}{60}=\frac{37}{60}\).
  5. \(\frac{13}{16}-\frac{7}{12}=\frac{39}{48}-\frac{28}{48}=\frac{11}{48}\).
  6. \(\frac{9}{14}+\frac{5}{21}=\frac{27}{42}+\frac{10}{42}=\frac{37}{42}\).