Решебник по математике 6 класс Виленкин Часть 1, 2 Часть 2. Задачи на повторение 1

\[\boxed{\mathbf{П.\ 1}}\]

\[1)\ \left( 1,8 + 1\frac{2}{7} \right)\ :\left( 1,8 - 1\frac{2}{7} \right) =\]

\[= \left( 1\frac{4}{5} + 1\frac{2}{7} \right)\ :\left( 1\frac{4}{5} - 1\frac{2}{7} \right) =\]

\[= \left( 1\frac{28}{35} + 1\frac{10}{35} \right)\ :\left( 1\frac{28}{35} - 1\frac{10}{35} \right) =\]

\[= 2\frac{38}{35}\ :\frac{18}{35} = \frac{108}{35}\ :\frac{18}{35} =\]

\[= \frac{108}{35} \cdot \frac{35}{18} = 6\]

\[2)\ \left( 1,5 + 1\frac{1}{3} \right)\ :\left( 7,6 - 5\frac{1}{3} \right) =\]

\[= \left( 1\frac{1}{2} + 1\frac{1}{3} \right)\ :\left( 7\frac{3}{5} - 5\frac{1}{3} \right) =\]

\[= \left( 1\frac{3}{6} + 1\frac{2}{6} \right)\ :\left( 7\frac{9}{15} - 5\frac{5}{15} \right) =\]

\[= 2\frac{5}{6}\ :2\frac{4}{15} = \frac{17}{6}\ :\frac{34}{15} =\]

\[= \frac{17}{6} \cdot \frac{15}{34} = \frac{5}{4} = 1,25\]

\[3)\ \left( 23 - 15\frac{1}{3} \right)\ :\left( - 5\frac{1}{9} \right) =\]

\[= 7\frac{2}{3}\ :\left( - \frac{46}{9} \right) = - \frac{23}{3} \cdot \frac{9}{46} =\]

\[= - \frac{3}{2} = - 1,5\]

\[4)\ \left( 19 - 13\frac{2}{3} \right)\ :\left( - 7\frac{1}{9} \right) =\]

\[= 5\frac{1}{3}\ :\left( - \frac{64}{9} \right) = - \frac{16}{3} \cdot \frac{9}{64} =\]

\[= - \frac{3}{4} = - 0,75\]