\[\frac{x - 3}{2} = \frac{2x}{7}\ \ \ \ \ \ \ \ | \cdot 14\]
\[7 \cdot (x - 3) = 2x \cdot 2\]
\[7x - 21 = 4x\]
\[7x - 4x = 21\]
\[3x = 21\]
\[x = 7.\]
\[Ответ:\ \ x = 7.\]