\[x^{2} + 8x + 15 = 0\]
\[x_{1} + x_{2} = - 8;\ \ x_{1} \cdot x_{2} = 15\]
\[x_{1} = - 5;\ \ x_{2} = - 3.\]
\[Корни\ нового\ уравнения:\]
\[x_{1} = - 5 + 2 = - 3;\]
\[x_{2} = - 3 + 2 = - 1.\]
\[Получаем:\]
\[x_{1} + x_{2} = - 3 - 1 = - 4;\]
\[x_{1} \cdot x_{2} = - 3 \cdot ( - 1) = 3.\]
\[Новое\ уравнение:\]
\[x^{2} + 4x + 3 = 0.\]