1) $$rac{8}{12} \cdot \frac{4}{5} - \frac{15}{37}$$

$$\frac{8}{12} \cdot \frac{4}{5} - \frac{15}{37} = \frac{2}{3} \cdot \frac{4}{5} - \frac{15}{37} = \frac{8}{15} - \frac{15}{37} =$$ $$\frac{8 \cdot 37 - 15 \cdot 15}{15 \cdot 37} = \frac{296 - 225}{555} = \frac{71}{555}$$