6. Solve (6/5-3/4)·2/3.

Решение: \(\left(\frac{6}{5} - \frac{3}{4}\right) \cdot \frac{2}{3} = \left(\frac{24}{20} - \frac{15}{20}\right) \cdot \frac{2}{3} = \frac{9}{20} \cdot \frac{2}{3} = \frac{18}{60} = \frac{3}{10}\). Ответ: \(\frac{3}{10}\).