The real zeros of the polynomial \( P(x) = x^4 - 8x^3 + 8x^2 + 23x + 6 \) are:
\[ x = -1, \quad x = 6, \quad x = \frac{3 - \sqrt{13}}{2}, \quad x = \frac{3 + \sqrt{13}}{2} \]
In decimal form, these are approximately:
\[ x = -1.0000, \quad x = 6.0000, \quad x = -0.3028, \quad x = 3.3028 \]
\(\boxed{x = -1, \quad x = 6, \quad x = \frac{3 - \sqrt{13}}{2}, \quad x = \frac{3 + \sqrt{13}}{2}}\)