ГДЗ по математике 6 класс Мерзляк Задание 609

\[\boxed{\mathbf{609\ (609)}\mathbf{.}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]

Пояснение.

Решение.

\[1)\ x\ :5 = 21\ :15\]

\[15 \cdot x = 21 \cdot 5\]

\[x = \frac{21 \cdot 5}{15} = \frac{21}{3}\]

\[x = 7\]

\[Ответ:7.\]

\[2)\ \frac{12}{x} = \frac{8}{18}\]

\[8 \cdot x = 18 \cdot 12\]

\[x = \frac{18 \cdot 12}{8} = 9 \cdot 3\]

\[x = 27\]

\[Ответ:27.\]

\[3)\ 4,5\ :0,6 = x\ :2,4\]

\[0,6 \cdot x = 2,4 \cdot 4,5\]

\[x = 2,4 \cdot 4,5\ :0,6\]

\[x = \frac{24}{10} \cdot \frac{45}{10}\ :\frac{6}{10}\]

\[x = 18\]

\[Ответ:18.\]

\[4)\ \frac{3,4}{5,1} = \frac{1,4}{x}\]

\[3,4 \cdot x = 1,4 \cdot 5,1\]

\[x = 1,4 \cdot 5,1\ :3,4\]

\[x = \frac{14}{10} \cdot \frac{51}{10}\ :\frac{34}{10}\]

\[x = \frac{21}{10}\]

\[x = 2,1\]

\[Ответ:2,1.\]