259. La expresión $\left[ \left( \frac{2}{3}-\frac{3}{2} \right):\left( \frac{1}{4}+\frac{5}{2} \right) \right]\cdot \frac{33}{10}$ es igual a

a) -1

b) ${}^{-10}\!\!\diagup\!\!{}_{33}\;$

c) ${}^{5}\!\!\diagup\!\!{}_{6}\;$

Operando:

$\left[ \left( \frac{2}{3}-\frac{3}{2} \right):\left( \frac{1}{4}+\frac{5}{2} \right) \right]\cdot \frac{33}{10}\quad =$

$=\quad \left[ \left( \frac{2\times 2}{3\times 2}-\frac{3\times 3}{2\times 3} \right):\left( \frac{1}{4}+\frac{5\times 2}{2\times 2} \right) \right]\cdot \frac{33}{10}\quad =$

$=\quad \left[ \left( \frac{4}{6}-\frac{9}{6} \right):\left( \frac{1}{4}+\frac{10}{4} \right) \right]\cdot \frac{33}{10}\quad =$

$=\quad \left[ \left( \frac{4-9}{6} \right):\left( \frac{1+10}{4} \right) \right]\cdot \frac{33}{10}\quad =\left[ \left( \frac{-5}{6} \right):\left( \frac{11}{4} \right) \right]\cdot \frac{33}{10}\quad =$

\[=\left[ \left( \frac{-5}{6} \right)\times \left( \frac{4}{11} \right) \right]\cdot \frac{33}{10}\quad =\frac{\left( -5 \right)\times 4\times 33}{6\times 11\times 10}\quad =\]