ГДЗ по математике 6 класс Мерзляк ФГОС Решаем устно параграф 9

\[\boxed{\mathbf{1}.}\]

\[1)\ \left( 1 - \frac{3}{4} \right) \cdot 12 = \frac{1}{4} \cdot 12 = 3\]

\[2)\ \left( 1 - \frac{1}{7} \right)\ :6 = \frac{6}{7} \cdot \frac{1}{6} = \frac{1}{7}\]

\[\boxed{\mathbf{2}.}\]

\[1)\ 3a \cdot \frac{1}{6}b = 3 \cdot \frac{1}{6}ab = \frac{1}{2}\text{ab}\]

\[2)\ 8x \cdot \frac{1}{24}y = 8 \cdot \frac{1}{24}xy = \frac{1}{3}\text{xy}\]

\[\boxed{\mathbf{3}.}\]

\[1)\ \frac{1}{5}x = 5\]

\[x = 5\ :\frac{1}{5} = 5 \cdot 5\]

\[x = 25.\]

\[2)\ 7\ :x = \frac{1}{7}\]

\[x = 7\ :\frac{1}{7} = 7 \cdot 7\]

\[x = 49.\]

\[\boxed{\mathbf{4}.}\]

\[2)\ 4 \cdot 66 = 4 \cdot 2 \cdot 33 = 8 \cdot 33\]

\[\boxed{\mathbf{5}.}\]

\[1)\ \frac{285}{341} - нельзя.\]

\[2)\ \frac{1902}{2754} - можно.\]

\[\boxed{\mathbf{6}.}\]

\[Сократимая\ (на\ 9\ и\ на\ 3):\]

\[\frac{4563}{10^{3} - 1} = \frac{4563}{999}.\]