\[\frac{5}{x^{2} + 3x} - \frac{15}{x^{2} - 3x} = \frac{16}{x}\]
\[8x² + 5x - 42 = 0\]
\[D = 25 + 1344 = 1369 = 37^{2}\]
\[x_{1} = \frac{- 5 + 37}{16} = 2;\ \ \ \]
\[x_{2} = \frac{- 5 - 37}{16} = - \frac{42}{16} =\]
\[= - \frac{21}{8} = - 2\frac{5}{8}.\]
\[Ответ:x = 2;\ x = - 2\frac{5}{8}.\]