Сложите дроби. 4. а) 1/8 + 3/7; б) 4/5 + 1/3; в) 2/3 + 2/6; г) 3/10 + 1/9.

1. \(\frac{1}{8}+\frac{3}{7}=\frac{7}{56}+\frac{24}{56}=\frac{31}{56}\).
2. \(\frac{4}{5}+\frac{1}{3}=\frac{12}{15}+\frac{5}{15}=\frac{17}{15}=1\frac{2}{15}\).
3. \(\frac{2}{3}+\frac{2}{6}=\frac{2}{3}+\frac{1}{3}=1\).
4. \(\frac{3}{10}+\frac{1}{9}=\frac{27}{90}+\frac{10}{90}=\frac{37}{90}\).

Ответ: а) \(\frac{31}{56}\); б) \(1\frac{2}{15}\); в) \(1\); г) \(\frac{37}{90}\).