\[\frac{x - 4}{4} = \frac{x + 3}{7}\]
\[7 \cdot (x - 4) = 4 \cdot (x + 3)\]
\[7x - 28 = 4x + 12\]
\[7x - 4x = 12 + 28\]
\[3x = 40\]
\[x = \frac{40}{3} = 16\frac{2}{3}.\]
\[Ответ:x = 16\frac{2}{3}.\]