Ответ:

  1. \(\frac56+\frac27=\frac{35}{42}+\frac{12}{42}=\frac{47}{42}=1\frac5{42}\).
  2. \(\frac{11}{25}-\frac3{10}=\frac{22}{50}-\frac{15}{50}=\frac7{50}\).
  3. \(\frac{15}{16}-\frac34=\frac{15}{16}-\frac{12}{16}=\frac3{16}\).
  4. \(\frac3{20}+\frac7{15}=\frac9{60}+\frac{28}{60}=\frac{37}{60}\).
  5. \(\frac{13}{16}-\frac7{12}=\frac{39}{48}-\frac{28}{48}=\frac{11}{48}\).
  6. \(\frac9{14}+\frac5{21}=\frac{27}{42}+\frac{10}{42}=\frac{37}{42}\).