I) Выполните действие: 1) 3/8 + 1/6; 2) 1/12 + 1/10; 3) 12/17 + 27/34; 4) 5/18 + 7/30; 5) 11/25 + 13/30; 6) 6/7 − 2/3; 7) 11/16 − 5/12; 8) 7/24 − 5/18; 9) 9/20 − 5/12; 10) 0,8 − 4/15.

Чтобы сложить или вычесть дроби, приводим их к общему знаменателю.

1. \(\frac{3}{8}+\frac{1}{6}=\frac{9}{24}+\frac{4}{24}=\frac{13}{24}\).
2. \(\frac{1}{12}+\frac{1}{10}=\frac{5}{60}+\frac{6}{60}=\frac{11}{60}\).
3. \(\frac{12}{17}+\frac{27}{34}=\frac{24}{34}+\frac{27}{34}=\frac{51}{34}\).
4. \(\frac{5}{18}+\frac{7}{30}=\frac{25}{90}+\frac{21}{90}=\frac{46}{90}=\frac{23}{45}\).
5. \(\frac{11}{25}+\frac{13}{30}=\frac{66}{150}+\frac{65}{150}=\frac{131}{150}\).
6. \(\frac{6}{7}-\frac{2}{3}=\frac{18}{21}-\frac{14}{21}=\frac{4}{21}\).
7. \(\frac{11}{16}-\frac{5}{12}=\frac{33}{48}-\frac{20}{48}=\frac{13}{48}\).
8. \(\frac{7}{24}-\frac{5}{18}=\frac{21}{72}-\frac{20}{72}=\frac{1}{72}\).
9. \(\frac{9}{20}-\frac{5}{12}=\frac{27}{60}-\frac{25}{60}=\frac{2}{60}=\frac{1}{30}\).
10. \(0,8-\frac{4}{15}=\frac{4}{5}-\frac{4}{15}=\frac{12}{15}-\frac{4}{15}=\frac{8}{15}\).

Ответ: 1) 13/24; 2) 11/60; 3) 51/34; 4) 23/45; 5) 131/150; 6) 4/21; 7) 13/48; 8) 1/72; 9) 1/30; 10) 8/15.