В: 3/5 + 4/5 =; 1 − 2/7 =; 4 2/5 + 2 1/5 =; 3 8/11 − 1 6/11 =; 5/7 + 2 =.

1. \(\frac{3}{5}+\frac{4}{5}=\frac{7}{5}=1\frac{2}{5}\)
2. \(1-\frac{2}{7}=\frac{7}{7}-\frac{2}{7}=\frac{5}{7}\)
3. \(4\frac{2}{5}+2\frac{1}{5}=6\frac{3}{5}\)
4. \(3\frac{8}{11}-1\frac{6}{11}=2\frac{2}{11}\)
5. \(\frac{5}{7}+2=2\frac{5}{7}\)

Ответ: \(1\frac{2}{5};\ \frac{5}{7};\ 6\frac{3}{5};\ 2\frac{2}{11};\ 2\frac{5}{7}\).