\[\boxed{Страница\ 29.}\]
\[\boxed{\mathbf{1.}}\]
\[\textbf{а)}\ 400\ :20 < 414\ :18 < 500\ :10\]
\[20 < 414\ :18 < 50\]
\[\textbf{б)}\ 12\ 000\ :60 < 13\ 272\ :56 < 15\ 000\ :50\]
\[200 < 13\ 272\ :56 < 300\]
\[\boxed{\mathbf{2.}}\]
\[\textbf{а)}\ 9000\ :30 < 9624\ :24 < 10\ 000\ :20\]
\[300 < 9624\ :24 < 500\]
\[400 < 37\ 914\ :89 < 500\]
\[\boxed{\mathbf{3.}}\]
\[= 123\ 055\]
\[1)\ 259\ 480 - 15\ 880 = 243\ 600\]
\[2)\ 107 \cdot 600 = 64\ 200\]
\[3)\ 243\ 600\ :8 = 30\ 450\]
\[4)\ 89\ 305 + 64\ 200 = 153\ 505\]
\[5)\ 153\ 505 - 30\ 450 = 123\ 055\]
\[\boxed{\mathbf{4.}}\]
\[\textbf{а)}\ 0 \leq n < 3\]
\[n = \left\{ 0;1;2 \right\}.\]
\[\textbf{б)}\ 4 \leq m < 8\]
\[m = \left\{ 4;5;6;7 \right\}.\]
\[\boxed{\mathbf{5.}}\]
\[Пусть\ x\ лет - Оле;\ \ \]
\[4x\ лет - Юре.\]
\[x + 6 = 4x\]
\[4x - x = 6\]
\[3x = 6\]
\[x = 6\ :3 = 2\ (года) - Оле.\]
\[4 \cdot 2 = 8\ (лет) - Юре.\]
\[Ответ:2\ года;8\ лет.\]