\[x^{2} - 8x + 15 = 0\]
\[x_{1} + x_{2} = 8;\ \ x_{1} \cdot x_{2} = 15\]
\[x_{1} = 3;\ \ x_{2} = 5.\]
\[В\ новом\ уравнении:\]
\[x_{1} = 3 - 2 = 1;x_{2} = 5 - 2 = 3;\]
\[x_{1} + x_{2} = 4;\ \ \ x_{1} \cdot x_{2} = 3;\]
\[x^{2} - 4x + 3 = 0.\]
\[Ответ:x^{2} - 4x + 3 = 0.\]