Ответ:

\(\frac{4}{9}-\frac{8}{27}=\frac{12}{27}-\frac{8}{27}=\frac{4}{27}\).

\(\frac{3}{16}\cdot\frac{4}{27}=\frac{12}{432}=\frac{1}{36}\).

Ответ: \(\frac{1}{36}\).