\[y = 6\frac{1}{3}:\]
\[- 4,7 - y = - 4\frac{7}{10} - 6\frac{1}{3} =\]
\[= - \left( 4\frac{21}{30} + 6\frac{10}{30} \right) = - 10\frac{31}{30} =\]
\[= - 11\frac{1}{30}.\]