Вычислите сумму смешанных чисел: а) 2 3/7 + 4 1/7; б) 5 1/6 + 3 5/6; в) 1 2/5 + 2 4/5; г) 6 7/11 + 1 5/11.

1. \(2\frac{3}{7}+4\frac{1}{7}=(2+4)+\left(\frac{3}{7}+\frac{1}{7}\right)=6+\frac{4}{7}=6\frac{4}{7}\).
2. \(5\frac{1}{6}+3\frac{5}{6}=(5+3)+\left(\frac{1}{6}+\frac{5}{6}\right)=8+1=9\).
3. \(1\frac{2}{5}+2\frac{4}{5}=(1+2)+\left(\frac{2}{5}+\frac{4}{5}\right)=3+\frac{6}{5}=4\frac{1}{5}\).
4. \(6\frac{7}{11}+1\frac{5}{11}=(6+1)+\left(\frac{7}{11}+\frac{5}{11}\right)=7+\frac{12}{11}=8\frac{1}{11}\).

Ответ: а) \(6\frac{4}{7}\); б) \(9\); в) \(4\frac{1}{5}\); г) \(8\frac{1}{11}\).