\[7\sqrt{6} - 2\sqrt{54} + \sqrt{96} =\]
\[= 7\sqrt{6} - 2\sqrt{6 \cdot 9} + \sqrt{6 \cdot 16} =\]
\[= 7\sqrt{6} - 6\sqrt{6} + 4\sqrt{6} = 5\sqrt{6}\]