Ответ: -2; 4
\[x^2 - 2x - 8 = 0\]
\[D = (-2)^2 - 4 \cdot 1 \cdot (-8) = 4 + 32 = 36\]
\[x_1 = \frac{-b + \sqrt{D}}{2a}, \quad x_2 = \frac{-b - \sqrt{D}}{2a}\]
\[x_1 = \frac{2 + \sqrt{36}}{2 \cdot 1} = \frac{2 + 6}{2} = \frac{8}{2} = 4\]
\[x_2 = \frac{2 - \sqrt{36}}{2 \cdot 1} = \frac{2 - 6}{2} = \frac{-4}{2} = -2\]
Ответ: -2; 4