Вычислите: -5/16*4/7-21/32:(-9/4).

\[- \frac{5}{16} \cdot \frac{4}{7} - \frac{21}{32}\ :\left( - \frac{9}{4} \right) =\]

\[= - \frac{5}{28} + \frac{21}{32} \cdot \frac{4}{9} = - \frac{5}{28} + \frac{7}{8 \cdot 3} =\]

\[= - \frac{5^{\backslash 6}}{28} + \frac{7^{\backslash 7}}{24} = \frac{49 - 30}{168} = \frac{19}{168}.\]