\[x^{2} - 4x - 10 = 0\]
\[\left\{ \begin{matrix} x_{1} + x_{2} = 4\ \ \ \ \\ x_{1} \cdot x_{2} = - 10 \\ \end{matrix} \right.\ \]
\[1)\ x_{1} - 4 + x_{2} + 4 =\]
\[= x_{1} + x_{2} - 8 = 4 - 8 = - 4\]
\[b = 4.\]
\[2)\ \left( x_{1} - 4 \right)\left( x_{2} - 4 \right) =\]
\[= x_{1}x_{2} - 4x_{1} - 4x_{2} + 16 =\]
\[= x_{1}x_{2} - 4 \cdot \left( x_{1} + x_{2} \right) + 16 =\]
\[= - 10 - 4 \cdot 4 + 16 =\]
\[= - 10 - 16 + 16 = - 10\]
\[c = - 10.\]
\[Получаем\ уравнение:\ \]
\[x^{2} + 4x - 10 = 0.\]