[tex]a = \sqrt{3}( \sqrt{27} + \sqrt{75} - \sqrt{243}) + 2 \sqrt{3} \times \sqrt{48} \\ \\ a = \sqrt{3}(3 \sqrt{3} + 5 \sqrt{3} - 9 \sqrt{3}) + 2 \sqrt{3} \times \sqrt{48} \\ \\ a = \sqrt{3} \times - \sqrt{3} + 2 \sqrt{3} \times 4 \sqrt{3} \\ \\ a = - \sqrt{3} \sqrt{3} + 2 \sqrt{3} \times 4 \sqrt{3} \\ \\ a = - \sqrt{9} + 2 \sqrt{3} \times 4 \sqrt{3} \\ \\ a = - 3 + 2 \sqrt{3} \times 4 \sqrt{3} \\ \\ a = - 3 + 2 \times 4 \sqrt{3 \times 3} \\ \\ a = - 3 + 2 \times 4 \sqrt{9} \\ \\ a = - 3 + 2 \times 4 \times 3 \\ \\ a = - 3 + 24 \\ \\ a = 21 [/tex]
