\[\boxed{\mathbf{341}.}\]
\[x^{4} + 2x^{3} - 16x^{2} - 2x + 15 = 0\]
\[x_{1};x_{2};x_{3};x_{4} - корни\ \]
\[уравнения.\]
\[Пусть\ x_{1} = - y_{1};\ \ x_{2} = - y_{2};\ \]
\[\ x_{3} = - y_{3};\ \ x_{4} = - y_{4}.\]
\[Подставим:\]
\[1)\ y_{1} + y_{2} + y_{3} + y_{4} = 2;\]
\[2)\ y_{1}y_{2} + y_{2}y_{3} + y_{3}y_{4} +\]
\[+ y_{2}y_{4} + y_{1}y_{4}y_{1}y_{3} = - 16;\]
\[3)\ y_{1}y_{2}y_{3} + y_{2}y_{3}y_{4} + y_{1}y_{2}y_{4} +\]
\[+ y_{1}y_{3}y_{4} = - 2;\]
\[4)\ y_{1}y_{2}y_{3}y_{4} = - x_{1}x_{2}x_{3} = 15.\]
\[Получаем\ уравнение:\]
\[x^{4} - 2x^{3} - 16x^{2} + 2x +\]
\[+ 15 = 0.\]