Question

căn 5 + 2 căn 6          -              căn 5 - 2 căn 6

Answer 1

\(\sqrt{5}+2\sqrt{6}-\left(\sqrt{5}-2\sqrt{6}\right)=4\sqrt{6}\)

Answer 2

`\sqrt{5+2\sqrt{6}}-\sqrt{5-2\sqrt{6}}`

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

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

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

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

`=2\sqrt{2}`

Answer 3

\(\sqrt{5+2\sqrt{6}}-\sqrt{5-2\sqrt{6}}\)

\(=\sqrt{3}+\sqrt{2}-\sqrt{3}+\sqrt{2}\)

\(=2\sqrt{2}\)