\[\frac{1 - 2x}{3} - \frac{x + 3}{4} = \frac{2 - 4x}{5}\ \ \ \ \ \ \ \ \ \ | \cdot 60\]
\[20 \cdot (1 - 2x) - 15 \cdot (x + 3) = 12 \cdot (2 - 4x)\]
\[20 - 40x - 15x - 45 = 24 - 48x\]
\[- 55x + 48x = 24 + 25\]
\[- 7x = 49\]
\[x = 49\ :( - 7)\]
\[x = - 7.\]
\[Ответ:x = - 7.\]