Решебник по математике 6 класс Виленкин Часть 1, 2 Часть 2. Параграф 4. Действия с рациональными числами Задание 317

\[\boxed{\text{4.\ 317}}\]

\[\textbf{а)}\frac{- 4,5}{- 0,9} = \frac{45}{9} = 5\]

\[\textbf{б)}\ \frac{- 9,4}{4,7} = - \frac{94}{47} = - 2\]

\[\textbf{в)}\ \frac{2,1}{- 6,3} = - \frac{21}{63} = - \frac{1}{3}\]

\[\textbf{г)}\ \frac{- 1,7}{8,5} = - \frac{17}{85} = - \frac{1}{5} = - 0,2\]

\[\textbf{д)}\ \frac{7,2 \cdot ( - 1,9)}{- 5,7 \cdot 8} = \frac{72 \cdot 19}{57 \cdot 8} =\]

\[= \frac{9}{3} = 3\]

\[\textbf{е)}\ 0,63\ :\left( - \frac{7}{9} \right) = - \frac{63}{10} \cdot \frac{9}{7} =\]

\[= - \frac{81}{10} = - 8,1\]

\[\textbf{ж)} - 1,25\ :1\frac{9}{16} = - \frac{125}{100}\ :\frac{25}{16} =\]

\[= - \frac{5}{4} \cdot \frac{16}{25} = - \frac{4}{5} = - 0,8\]

\[\textbf{з)}\ \frac{5\frac{3}{7}\ }{- 1\frac{5}{14}} = \frac{38}{7}\ :\left( - \frac{19}{14} \right) =\]

\[= - \frac{38}{7} \cdot \frac{14}{19} = - 2 \cdot 2 = - 4\]

\[\textbf{и)}\ \frac{- 1\frac{1}{7}}{3\frac{1}{14}} = - \frac{8}{7}\ :\frac{43}{14} = - \frac{8}{7} \cdot \frac{14}{43} =\]

\[= - \frac{16}{43}\]