\[(x + 1)(y + 2)(z + 8) \geq 32\sqrt{\text{xyz}};\ \ \ \]
\[x \geq 0,\ y \geq 0,\ z \geq 0\]
\[\frac{x + 1}{2} \cdot \frac{y + 2}{2} \cdot \frac{z + 8}{2} \geq 4\sqrt{\text{xyz}}\]
\[\sqrt{x} \cdot \sqrt{2y} \cdot \sqrt{8z} - 4\sqrt{\text{xyz}} \geq 0\]
\[\sqrt{16xyz} - 4\sqrt{\text{xyz}} \geq 0\]
\[\sqrt{16xyz} - \sqrt{16xyz} \geq 0 \Longrightarrow\]
\[\Longrightarrow верно.\]