\[\frac{1}{4} + \frac{5}{12} = \frac{3}{12} + \frac{5}{12} = \frac{8}{12} = \frac{2}{3}\]
\[\frac{9}{16} \cdot \frac{2}{3} = \frac{9 \cdot 2}{16 \cdot 3} = \frac{18}{48} = \frac{3}{8}\]
\[\frac{3}{8} : \frac{8}{15} = \frac{3}{8} \cdot \frac{15}{8} = \frac{3 \cdot 15}{8 \cdot 8} = \frac{45}{64}\]
\[\frac{45}{64} - \frac{16}{45} = \frac{45 \cdot 45}{64 \cdot 45} - \frac{16 \cdot 64}{45 \cdot 64} = \frac{2025}{2880} - \frac{1024}{2880} = \frac{1001}{2880}\]
Ответ: \(\frac{1001}{2880}\)