\[c = - 3\frac{2}{35}:\]
\[- 5,7 - c = - 5,7 - \left( 3\frac{2}{35} \right) =\]
\[= - 5\frac{7}{10} + 3\frac{2}{35} =\]
\[= - \left( 5\frac{49}{70} - 3\frac{4}{70} \right) =\]
\[= - 2\frac{45}{70} = - 2\frac{9}{14}.\]