\[\boxed{\text{5.\ 24}}\]
\[1)\ 2,5x\ :14 = \frac{1}{7}\ :30\]
\[2,5x \cdot 30 = 14 \cdot \frac{1}{7}\]
\[75x = 2\]
\[x = \frac{2}{75}.\]
\[2)\ 36\ :35 = \frac{1}{5}x\ :\frac{1}{12}\]
\[\frac{1}{5}x \cdot 35 = 36 \cdot \frac{1}{12}\]
\[7x = 3\]
\[x = \frac{3}{7}.\]