Ответ:

\(\frac{2}{9}+\frac{4}{9}=\frac{6}{9}=\frac{2}{3}\).

\(\frac{5}{12}+\frac{3}{12}=\frac{8}{12}=\frac{2}{3}\).

\(\frac{1}{6}+\frac{5}{6}=\frac{6}{6}=1\).

Ответ: \(\frac{2}{3};\ \frac{2}{3};\ 1\).