\[\frac{x^{3}}{|x|} + x + 3 = 0\]
\[1)\ x > 0:\]
\[\frac{x^{3}}{x} + x + 3 = 0\]
\[x^{2} + x + 3 = 0\]
\[D = b^{2} - 4ac = 1 - 4 \cdot 1 \cdot 3 =\]
\[= 1 - 12 = - 11 < 0\]
\[нет\ решений.\]
\[2)\ x < 0:\]
\[\frac{x^{3}}{- x} + x + 3 = 0\]
\[- x^{2} + x + 3 = 0\]
\[x^{2} - x - 3 = 0\]
\[D = b^{2} - 4ac =\]
\[= 1 - 4 \cdot ( - 1) \cdot 3 =\]
\[= 1 + 12 = 13\]
\[x_{1} = \frac{1 - \sqrt{13}}{2};\ \]
\[x_{2} = \frac{1 + \sqrt{13}}{2} > 0 -\]
\[не\ подходит.\]
\[Ответ:x = \frac{1 - \sqrt{13}}{2}.\]