\[\sqrt{6a} \cdot \sqrt{3b} \cdot \sqrt{2c} - 6\sqrt{\text{abc}} \geq 0\]
\[\sqrt{36abc} - 6\sqrt{\text{abc}} \geq 0\]
\[6\sqrt{\text{abc}} - 6\sqrt{\text{abc}} \geq 0 \Longrightarrow верно.\]