§ Задание 1128
\[\boxed{\mathbf{1128\ (1120)}\mathbf{.}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[- \frac{a}{b} = \frac{a}{- b} = \frac{- a}{b}\]
\[\frac{- a}{- b} = \frac{a}{b}\]
\[\boxed{\mathbf{1128\ (1120)}\mathbf{.}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[- \frac{a}{b} = \frac{a}{- b} = \frac{- a}{b}\]
\[\frac{- a}{- b} = \frac{a}{b}\]