Вычислите: -2/7*3/8+(-2/7)*5/8.

\[- \frac{2}{7} \cdot \frac{3}{8} + \left( - \frac{2}{7} \right) \cdot \frac{5}{8} = - \frac{2}{7} \cdot \left( \frac{3}{8} + \frac{5}{8} \right) =\]

\[= - \frac{2}{7} \cdot \frac{8}{8} = - \frac{2}{7} \cdot 1 = - \frac{2}{7}.\]