\[\boxed{Страница\ 36.}\]
\[\boxed{\mathbf{4.}}\]
\[Цена\ деления\ числового\ луча\ \]
\[равна:\]
\[\textbf{а)}\ c = (2 - 1)\ :4 = 1\ :4 = \frac{1}{4};\ \]
\[\textbf{б)}\ c = (72 - 36)\ :3 = 36\ :3 =\]
\[= 12;\]
\[\textbf{в)}\ c = (160 - 80)\ :5 = 80\ :5 =\]
\[= 16.\]
\[\boxed{\mathbf{5.}}\]
\[\textbf{а)}\ цена\ деления\ равна\ 5:\]
\[\textbf{б)}\ цена\ деления\ равна\frac{1}{8}:\]
\[\boxed{\mathbf{6.}}\]
\[\textbf{а)}\ \left( 5\frac{6}{15} + x \right) - \frac{12}{15} = 7\frac{3}{15}\]
\[5\frac{6}{15} + x = 7\frac{3}{15} + \frac{12}{15}\]
\[5\frac{6}{15} + x = 7\frac{15}{15}\]
\[x = 7\frac{15}{15} - 5\frac{6}{15}\]
\[x = 2\frac{9}{15}.\]
\[\textbf{б)}\ \left( y - 3\frac{7}{9} \right) + 6\frac{4}{9} = 8\frac{1}{9}\]
\[y - 3\frac{7}{9} = 7\frac{10}{9} - 6\frac{4}{9}\]
\[y - 3\frac{7}{9} = 1\frac{6}{9}\]
\[y = 1\frac{6}{9} + 3\frac{7}{9}\]
\[y = 4\frac{13}{9}\]
\[y = 5\frac{4}{9}.\]
\[\boxed{\mathbf{7.}}\]
\[62\ 317\]
\[\textbf{а)}\ наименьшее\ число:\]
\[2317;\]
\[\textbf{б)}\ наибольшее\ число:\]
\[6317.\]