\[\boxed{\mathbf{Проверочная\ работа\ №2.\ Действие\ деления}}\]
\[\boxed{\mathbf{1.}}\]
\[7\ :\frac{1}{3} = 7 \cdot 3 = 21.\]
\[\boxed{\mathbf{2.}}\]
\[\frac{3}{7}\ :2 = \frac{3}{7} \cdot \frac{1}{2} = \frac{3}{14}.\]
\[\boxed{\mathbf{3.}}\]
\[\frac{1}{5}\ :\frac{2}{3} = \frac{1}{5} \cdot \frac{3}{2} = \frac{3}{10} = 0,3.\]
\[\boxed{\mathbf{4.}}\]
\[\frac{4}{9}\ :4 = \frac{4}{9} \cdot \frac{1}{4} = \frac{1}{9}.\]
\[\boxed{\mathbf{5.}}\]
\[6\frac{3}{5}\ :3 = \frac{33}{5} \cdot \frac{1}{3} = \frac{11}{5} = 2\frac{1}{5} =\]
\[= 2,2.\]
\[\boxed{\mathbf{6.}}\]
\[\frac{3}{8}\ :x = 3\]
\[x = \frac{3}{8}\ :3 = \frac{3}{8} \cdot \frac{1}{3}\]
\[x = \frac{1}{8}\]
\[Ответ:на\ \frac{1}{8}.\]
\[\boxed{\mathbf{7.}}\]
\[1\ :\frac{2}{7} = 1 \cdot \frac{7}{2} = 3,5 \neq 1.\]
\[\mathbf{Нет.\ }\]
\[\boxed{\mathbf{8.}}\]
\[5\ :\frac{2}{5} = 5 \cdot \frac{5}{2} = \frac{25}{2} = 12\frac{1}{2} = 12,5.\]
\[Да.\]