\[y = \frac{2x + 3}{3 - x};\ \ y = 4:\]
\[\frac{2x + 3}{3 - x} = 4;\ \ \ x \neq 3\]
\[2x + 3 = 4(3 - x)\]
\[2x + 3 = 12 - 4x\]
\[6x = 9\]
\[x = 1,5.\]
\[Ответ:при\ x = 1,5.\]