5/căn6+1 + 3căn3-5căn5/căn5-căn3 -6/căn 6

ét ô ét mng ơi :>>>

Đáp án:

$\dfrac{5}{\sqrt{6}+1}+\dfrac{3\sqrt{3}-5\sqrt{5}}{\sqrt{5}-\sqrt{3}}-\dfrac{6}{\sqrt{6}}=-9-\sqrt{15}$

Giải thích các bước giải:

$\dfrac{5}{\sqrt{6}+1}+\dfrac{3\sqrt{3}-5\sqrt{5}}{\sqrt{5}-\sqrt{3}}-\dfrac{6}{\sqrt{6}}\\=\dfrac{5(\sqrt{6}-1)}{(\sqrt{6}-1)(\sqrt{6}+1)}+\dfrac{(\sqrt{3}-\sqrt{5})(3+\sqrt{15}+5)}{-(\sqrt{3}-\sqrt{5})}-\sqrt{6}\\=\sqrt{6}-1-(8+\sqrt{15})-\sqrt{6}\\=-9-\sqrt{15}$