[tex] {( \sqrt{6} + 3) }^{3} = \\ \\ ( \sqrt{6} + 3)( { \sqrt{6} }^{2} + 2 \sqrt{6} \times 3 + {3}^{2}) = \\ \\ ( \sqrt{6} + 3)(6 + 6 \sqrt{6} + 9) = \\ \\ ( \sqrt{6} + 3)(15 + 6\sqrt{6}) = \\ \\ 15 \sqrt{6} + 36 + 45 + 18 \sqrt{6} = \\ \\ (15 \sqrt{6} + 18 \sqrt{6}) + (36 + 45) = \\ \\ 33 \sqrt{6} + 81 [/tex]
