Question

rút gọn biểu thức

 

Answer 1

`5)\sqrt{5+2\sqrt{6}}+\sqrt{8-2\sqrt{15}}`

`=\sqrt{3+2\sqrt{3}\sqrt{2}+2}+\sqrt{5-2\sqrt{5}\sqrt{3}+3}`

`=\sqrt{(\sqrt{3}+\sqrt{2})^2}+\sqrt{(\sqrt{5}-\sqrt{3})^2}`

`=\sqrt{3}+\sqrt{2}+\sqrt{5}-\sqrt{3}`

`=\sqrt{2}+\sqrt{5}`