61. Выполните сложение: а) \(\frac{3}{4}+\frac{2}{3}\); б) \(\frac{3}{10}+\frac{2}{15}\); в) \(\frac{4}{9}+\frac{1}{6}\); г) \(\frac{7}{15}+\frac{3}{40}\).

а) \[\frac{3}{4}+\frac{2}{3}=\frac{9}{12}+\frac{8}{12}=\frac{17}{12}=1\frac{5}{12}.\]

б) \[\frac{3}{10}+\frac{2}{15}=\frac{9}{30}+\frac{4}{30}=\frac{13}{30}.\]

в) \[\frac{4}{9}+\frac{1}{6}=\frac{8}{18}+\frac{3}{18}=\frac{11}{18}.\]

г) \[\frac{7}{15}+\frac{3}{40}=\frac{56}{120}+\frac{9}{120}=\frac{65}{120}=\frac{13}{24}.\]

Ответ: а) \(1\frac{5}{12}\); б) \(\frac{13}{30}\); в) \(\frac{11}{18}\); г) \(\frac{13}{24}\).