Решение:
1. $\frac{1}{4} + \frac{5}{12} = \frac{3}{12} + \frac{5}{12} = \frac{8}{12} = \frac{2}{3}$
2. $\frac{9}{16} \cdot \frac{2}{3} = \frac{9 \cdot 2}{16 \cdot 3} = \frac{18}{48} = \frac{3}{8}$
3. $\frac{8}{15} : \frac{16}{45} = \frac{8}{15} \cdot \frac{45}{16} = \frac{8 \cdot 45}{15 \cdot 16} = \frac{360}{240} = \frac{3}{2}$
4. $\frac{3}{8} - \frac{3}{2} = \frac{3}{8} - \frac{12}{8} = -\frac{9}{8} = -1\frac{1}{8}$
**Ответ: -1 1/8**
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