[tex]\it \sqrt{18} - \sqrt{12} + 2\sqrt{27} - 3\sqrt{50} = 3\sqrt{2} - 2\sqrt{3} + 2 \cdot 3\sqrt{3} - 3 \cdot 5\sqrt{2} = \\ \\ 3\sqrt{2} - 2\sqrt{3} + 6\sqrt{3} - 15\sqrt{2} = -12\sqrt{2} + 4\sqrt{3} = 4\sqrt{3} - 12\sqrt{2} = 4(\sqrt{3} - 3\sqrt{2})[/tex]
