Đáp án: $a=\frac{29\sqrt{3}}{3}+3\sqrt{6}$
Giải thích các bước giải: a) $~~~~\sqrt{75}-\sqrt{5\frac{1}{3}}+\frac{9}{2}\times\sqrt{2\frac{2}{3}}+2\sqrt{27}\\=5\sqrt{3}-\sqrt{\frac{16}{3}}+\frac{9}{2}\times\sqrt{\frac{8}{3}}+6\sqrt{3}\\=5\sqrt{3}-\frac{4}{\sqrt{3}}+\frac{9}{2}\times\frac{\sqrt{8}}{\sqrt{3}}+6\sqrt{3}\\=5\sqrt{3}-\frac{4\sqrt{3}}{3}+\frac{9}{2}\times\frac{2\sqrt{2}}{\sqrt{3}}+6\sqrt{3}\\=5\sqrt{3}-\frac{4\sqrt{3}}{3}+9\times\frac{\sqrt{2}}{\sqrt{3}}+6\sqrt{3}\\=5\sqrt{3}-\frac{6\sqrt{3}}{3}+\frac{9\sqrt{2}}{\sqrt{3}}+6\sqrt{3}\\=5\sqrt{3}-\frac{4\sqrt{3}}{3}+3\sqrt{6}+6\sqrt{3}\\=\frac{29\sqrt{3}}{3}+3\sqrt{6}\\\approx 24,09163$
