Đáp án:
Giải thích các bước giải:
$=\sqrt{\frac{(3\sqrt{3}-4)(2\sqrt{3}-1)}{(2\sqrt{3}+1)(2\sqrt{3}-1)}}-\sqrt{\frac{(\sqrt{3}+4)(5+2\sqrt{3})}{(5-2\sqrt{3})(5+2\sqrt{3})}}=\sqrt{\frac{22-11\sqrt{3}}{11}}-\sqrt{\frac{26+13\sqrt{3}}{13}}$
$=\sqrt{2-\sqrt{3}}-\sqrt{2+\sqrt{3}}=\frac{1}{\sqrt{2}}(\sqrt{4-2\sqrt{3}}-\sqrt{4+2\sqrt{3}})$
$=\frac{1}{\sqrt{2}}(\sqrt{(\sqrt{3}-1)^2}-\sqrt{(\sqrt{3}+1)^2}=\frac{1}{\sqrt{2}}(\sqrt{3}-1-\sqrt{3}-1)$
$=-\frac{2}{\sqrt{2}}=-\sqrt{2}$