Решебник по математике 6 класс Мерзляк ФГОС Задание 253

\[\boxed{\mathbf{253\ (253)}\mathbf{.}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]

\[1)\ \frac{8}{19} < \frac{x}{19} < 1\ \ \ \ \]

\[x = 9,\ 10,\ 11,\ 12,\ 13,\ 14,\ 15,\ 16,\ \]

\[17,\ 18.\]

\[2)\ \frac{1}{3} < \frac{x}{18} < \frac{5}{6}\text{\ \ \ }\]

\[\frac{6}{18} < \frac{x}{18} < \frac{15}{18}\text{\ \ \ \ }\]

\[x = 7,\ 8,\ 9,\ 10,\ 11,\ 12,\ 13,\ 14.\]

\[\boxed{\mathbf{253}\mathbf{.}}\]

\[P_{\text{ABC}} = 27\ см;\]

\[P_{\text{ADC}} = 22\ см;\]

\[P_{\text{ABCD}} = 31\ см;\]

\[AC - ?\]

\[P_{\text{ABCD}} = P_{\text{ABC}} + P_{\text{ADC}} - 2AC\]

\[31 = 27 + 22 - 2AC\]

\[49 - 2AC = 31\]

\[2AC = 49 - 31\]

\[2AC = 18\]

\[AC = 18\ :2 = 9\ см.\]

\[Ответ:9\ см.\]