[tex]90\sqrt3+2\sqrt3\cdot\{18\sqrt2-3\sqrt3[8\sqrt6-3(2\sqrt6-5\sqrt3)]\}=\\
90\sqrt3+2\sqrt3\cdot\{18\sqrt2-3\sqrt3\cdot[8\sqrt6-6\sqrt6+15\sqrt3]\}=\\
90\sqrt3+2\sqrt3\cdot\{18\sqrt2-3\sqrt3\cdot[2\sqrt6+15\sqrt3]\}=\\
90\sqrt3+2\sqrt3\cdot\{18\sqrt2-6\sqrt{18}-135\}=\\
90\sqrt3+2\sqrt3\cdot\{18\sqrt2-18\sqrt2-135\}=\\
90\sqrt3-270\sqrt3=-180\sqrt3\\
[/tex]