Bài dễ! ai giúp được thanks liền

T

th1104

Ta có:

$(4+\sqrt{15})(\sqrt{10} - \sqrt{6})\sqrt{4- \sqrt{15}}$

= $\sqrt{4 + \sqrt{15}}\sqrt{(4+\sqrt{15})(4-\sqrt{15})}(\sqrt{10} - \sqrt{6})$

= $\sqrt{4 + \sqrt{15}} (\sqrt{10} - \sqrt{6})$

= $\sqrt{(4+\sqrt{15})(\sqrt{10} - \sqrt{6})^2}$

= $\sqrt{(4+\sqrt{15}). 4 (4 - \sqrt{15})}$

= 2
 
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