$\frac{{{\left( \frac{2}{3} \right)}^{3}}\times {{\left( \frac{3}{8} \right)}^{3}}}{-{{2}^{-3}}}=\frac{{{\left( \frac{\overset{1}{\mathop{\cancel{2}}}\,}{\underset{1}{\mathop{\cancel{3}}}\,}\times \frac{\overset{1}{\mathop{\cancel{3}}}\,}{\underset{4}{\mathop{\cancel{8}}}\,} \right)}^{3}}}{-{{2}^{-3}}}$
$=\frac{{{\left( \frac{1}{4} \right)}^{3}}\times {{2}^{3}}}{-1}=\frac{{{\left( \frac{1}{\underset{2}{\mathop{\cancel{4}}}\,}\times \overset{1}{\mathop{\cancel{2}}}\, \right)}^{3}}}{-1}=-{{\left( \frac{1}{2} \right)}^{3}}=-\frac{1}{8}$