11. Упростите выражение: а) 12\sqrt{3} + 4\sqrt{3} - 8\sqrt{3} ;

11. Упростите выражение: a) $12\sqrt{3} + 4\sqrt{3} - 8\sqrt{3} = (12+4-8)\sqrt{3} = 8\sqrt{3}$ б) $7\sqrt{5} + 15\sqrt{5} - 9\sqrt{5} = (7+15-9)\sqrt{5} = 13\sqrt{5}$ в) $\sqrt{27} + 8\sqrt{3} + \sqrt{48} - \sqrt{75} = 3\sqrt{3} + 8\sqrt{3} + 4\sqrt{3} - 5\sqrt{3} = (3+8+4-5)\sqrt{3} = 10\sqrt{3}$ г) $\sqrt{18} - \sqrt{50} + \sqrt{288} - 2\sqrt{2} = 3\sqrt{2} - 5\sqrt{2} + 12\sqrt{2} - 2\sqrt{2} = (3-5+12-2)\sqrt{2} = 8\sqrt{2}$ д) $\frac{\sqrt{45} + \sqrt{80}}{\sqrt{245}} = \frac{3\sqrt{5} + 4\sqrt{5}}{7\sqrt{5}} = \frac{7\sqrt{5}}{7\sqrt{5}} = 1$ е) $\frac{\sqrt{175} - \sqrt{63}}{\sqrt{112}} = \frac{5\sqrt{7} - 3\sqrt{7}}{4\sqrt{7}} = \frac{2\sqrt{7}}{4\sqrt{7}} = 0,5$ ж) $\sqrt{\frac{1}{3}} + \sqrt{48} + \sqrt{\frac{1}{27}} = \frac{\sqrt{3}}{3} + 4\sqrt{3} + \frac{\sqrt{3}}{9} = \frac{3\sqrt{3} + 36\sqrt{3} + \sqrt{3}}{9} = \frac{40\sqrt{3}}{9}$ з) $\sqrt{0,5} + \sqrt{32} + \sqrt{\frac{1}{128}} = \sqrt{\frac{1}{2}} + 4\sqrt{2} + \sqrt{\frac{1}{128}} = \frac{\sqrt{2}}{2} + 4\sqrt{2} + \frac{1}{8\sqrt{2}} = \frac{\sqrt{2}}{2} + 4\sqrt{2} + \frac{\sqrt{2}}{16} = \frac{8\sqrt{2} + 64\sqrt{2} + \sqrt{2}}{16} = \frac{73\sqrt{2}}{16}$ 12. Найдите значение выражения: a) $\sqrt{8 \cdot 18} = \sqrt{144} = 12$ б) $\sqrt{98 \cdot 8} = \sqrt{784} = 28$ в) $\sqrt{24 \cdot 150} = \sqrt{3600} = 60$ г) $\sqrt{12 \cdot 15 \cdot 20} = \sqrt{3600} = 60$ д) $\sqrt{28 \cdot 63 \cdot 81} = \sqrt{4 \cdot 7 \cdot 9 \cdot 7 \cdot 81} = \sqrt{4 \cdot 9 \cdot 81 \cdot 49} = 2 \cdot 3 \cdot 9 \cdot 7 = 378$ е) $\sqrt{18 \cdot 512 \cdot 169} = \sqrt{9 \cdot 2 \cdot 256 \cdot 2 \cdot 169} = \sqrt{9 \cdot 256 \cdot 4 \cdot 169} = 3 \cdot 16 \cdot 2 \cdot 13 = 1248$