Đáp án:
Giải thích các bước giải:
`\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}`
`=(\sqrt{2}(\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}))/\sqrt{2`
`=(\sqrt{4+2\sqrt{3}}-\sqrt{4-2\sqrt{3}})/\sqrt{2`
`=(\sqrt{1+(\sqrt{3})^2+2\sqrt{3}}-\sqrt{1+(\sqrt{3})^2-2\sqrt{3}})/\sqrt{2`
`=(\sqrt{(1+\sqrt{3})^2}-\sqrt{(1-\sqrt{3})^2})/\sqrt{2`
`=(|1+\sqrt{3}|-|1-\sqrt{3}|)/\sqrt{2`
`=(1+\sqrt{3}-(\sqrt{3}-1))/\sqrt{2`
`=(1+\sqrt{3}+1-\sqrt{3})/\sqrt{2`
`=2/\sqrt{2}=\sqrt{2`
