2. Выполните действия: 1) 9/28 + 25/28; 2) 1 − 7/20; 3) 3 7/15 − 2 4/15; 4) 4 2/5 − 3/5; 5) 3/4 + 4/5; 6) 1 1/4 + 2 2/3.

1) \(\frac{9}{28}+\frac{25}{28}=\frac{34}{28}=1\frac{6}{28}=1\frac{3}{14}\).

2) \(1-\frac{7}{20}=\frac{20}{20}-\frac{7}{20}=\frac{13}{20}\).

3) \(3\frac{7}{15}-2\frac{4}{15}=1\frac{3}{15}=1\frac{1}{5}\).

4) \(4\frac{2}{5}-\frac{3}{5}=3\frac{7}{5}-\frac{3}{5}=3\frac{4}{5}\).

5) \(\frac{3}{4}+\frac{4}{5}=\frac{15}{20}+\frac{16}{20}=\frac{31}{20}=1\frac{11}{20}\).

6) \(1\frac{1}{4}+2\frac{2}{3}=3+\frac{3}{12}+\frac{8}{12}=3\frac{11}{12}\).

Ответ: 1) \(1\frac{3}{14}\); 2) \(\frac{13}{20}\); 3) \(1\frac{1}{5}\); 4) \(3\frac{4}{5}\); 5) \(1\frac{11}{20}\); 6) \(3\frac{11}{12}\).