Ответ:

а) \(\frac{5}{12}+\frac{1}{3}=\frac{5}{12}+\frac{4}{12}=\frac{9}{12}=\frac{3}{4}\).

б) \(\frac{11}{24}+\frac{3}{8}=\frac{11}{24}+\frac{9}{24}=\frac{20}{24}=\frac{5}{6}\).

в) \(\frac{5}{6}+\frac{1}{24}=\frac{20}{24}+\frac{1}{24}=\frac{21}{24}=\frac{7}{8}\).

г) \(\frac{57}{1000}+\frac{9}{10}=\frac{57}{1000}+\frac{900}{1000}=\frac{957}{1000}\).

Ответ: а) \(\frac{3}{4}\); б) \(\frac{5}{6}\); в) \(\frac{7}{8}\); г) \(\frac{957}{1000}\).