\[\boxed{\mathbf{956\ (956)}\mathbf{.}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[\textbf{а)}\ x > 0;\ \ y > 0\]
\[- \frac{x}{y} = - (x)\ :\left( \frac{1}{y} \right) < 0.\]
\[\textbf{б)}\ x < 0;\ \ y < 0:\]
\[- \frac{x}{y} = - (x) \bullet \frac{1}{y} < 0.\]
\[\textbf{в)}\ x > 0;\ \ y < 0:\]
\[- \frac{x}{y} = - x \bullet \frac{1}{y} > 0.\]