Bài làm :
a,
`\sqrt{(2-\sqrt{3})^2}+\sqrt{(1-\sqrt{3})^2}`
`=|2-\sqrt{3}|+|1-\sqrt{3}|`
`=2-\sqrt{3}+(\sqrt{3}-1)`
`=2-\sqrt{3}+\sqrt{3}-1`
`=(2-1)+(-\sqrt{3}+\sqrt{3})`
`=1+0`
`=1`
b,
`\sqrt{(3+\sqrt{2})^2}-\sqrt{(1-\sqrt{2})^2}`
`=|3+\sqrt{2}|-|1-\sqrt{2}|`
`=3+\sqrt{2}-(\sqrt{2}-1)`
`=3+\sqrt{2}-\sqrt{2}+1`
`=(3+1)+(\sqrt{2}-\sqrt{2})`
`=4+0`
`=4`
c,
`\sqrt{(\sqrt{5}-\sqrt{2})^2}+\sqrt{(\sqrt{5}+\sqrt{2})^2}`
`=|\sqrt{5}-\sqrt{2}|+|\sqrt{5}+\sqrt{2}|`
`=\sqrt{5}-\sqrt{2}+\sqrt{5}+\sqrt{2}`
`=(\sqrt{5}+\sqrt{5})+(-\sqrt{2}+\sqrt{2})`
`=2\sqrt{5}+0`
`=2\sqrt{5}`
d,
`\sqrt{(\sqrt{2}+1)^2}-\sqrt{(\sqrt{2}-5)^2}`
`=|\sqrt{2}+1|-|5-\sqrt{2}|`
`=\sqrt{2}+1-(5-sqrt{2})`
`=\sqrt{2}+1-5+\sqrt{2}`
`=(1-5)+(\sqrt{2}+\sqrt{2})`
`=-4+2\sqrt{2}`
