1. Вариант B-1. Выполните: 1) 2/8 + 5/8; 2) 12 3/8 + 8 1/6; 3) 7 5/6 − 3 2/3; 4) 6/35 + 3/10; 5) 11/48 − 5/36.

1. \(\frac{2}{8}+\frac{5}{8}=\frac{7}{8}\).
2. \(12\frac{3}{8}+8\frac{1}{6}=20+\frac{9}{24}+\frac{4}{24}=20\frac{13}{24}\).
3. \(7\frac{5}{6}-3\frac{2}{3}=7\frac{5}{6}-3\frac{4}{6}=4\frac{1}{6}\).
4. \(\frac{6}{35}+\frac{3}{10}=\frac{12}{70}+\frac{21}{70}=\frac{33}{70}\).
5. \(\frac{11}{48}-\frac{5}{36}=\frac{33}{144}-\frac{20}{144}=\frac{13}{144}\).

Ответ: 1) \(\frac{7}{8}\); 2) \(20\frac{13}{24}\); 3) \(4\frac{1}{6}\); 4) \(\frac{33}{70}\); 5) \(\frac{13}{144}\).