[tex] - 7(3 \sqrt{2} + \sqrt{3}) + 3( \sqrt{8} + \sqrt{12}) = \\ \\ - 7(3 \sqrt{2} + \sqrt{3}) + 3(2 \sqrt{2} + 2 \sqrt{3}) = \\ \\ - 21 \sqrt{2} - 7 \sqrt{3} + 6 \sqrt{2} + 6 \sqrt{3} = \\ \\ ( - 21 \sqrt{2} + 6 \sqrt{2}) + ( - 7 \sqrt{3} + 6 \sqrt{3}) = \\ \\ - 15 \sqrt{2} - \sqrt{3} [/tex]
