3)(-)=

3) $$\frac{18}{16} \cdot (-\frac{5}{6}) = \frac{3 \cdot 6}{8 \cdot 2} \cdot (-\frac{5}{6}) = \frac{3}{8} \cdot (-\frac{5}{1}) = -\frac{15}{8} = -1\frac{7}{8}$$

Ответ: $$-1\frac{7}{8}$$