19. \(\frac{11}{15}-\frac{2}{5}+\frac{1}{3}\)

\(\frac{11}{15}-\frac{2}{5}+\frac{1}{3}=\frac{11}{15}-\frac{6}{15}+\frac{5}{15}=\frac{10}{15}=\frac{2}{3}\).

Ответ: \(\frac{2}{3}\)