tính giá trị của cái biểu thức sau giúp em với ạ

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

`=``\sqrt{1+2\sqrt{5}+5}+\sqrt{1-2\sqrt{5}+5}`

`=``\sqrt{(\sqrt{5}+1)^2}+\sqrt{(\sqrt{5}-1)^2}`

`=|\sqrt{5}+1|+|\sqrt{5}-1|`

`=1+\sqrt{5}-1+\sqrt{5}`

`=2\sqrt{5}`

`b)` `\sqrt{3+2\sqrt{2}}+\sqrt{6-4\sqrt{2}}`

`=``\sqrt{1+2\sqrt{2}+2}+\sqrt{2-4\sqrt{2}+4}`

`=``\sqrt{(\sqrt{2}+1)^2}+\sqrt{(\sqrt{2}-2)^2}`

`=|\sqrt{2}+1|+|\sqrt{2}-2|`

`=1+\sqrt{2}+2-\sqrt{2}`

`=3`

`c)``\sqrt{24+8\sqrt{5}}+\sqrt{9-4\sqrt{5}}`

`=``\sqrt{20+8\sqrt{5}+4}+\sqrt{4-4\sqrt{5}+5}`

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

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

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

`=3\sqrt{5}`

`d)``\sqrt{41-12\sqrt{5}}-\sqrt{41+12\sqrt{5}}`

`=``\sqrt{5-12\sqrt{5}+36}-\sqrt{5+12\sqrt{5}+36}`

`=``\sqrt{(\sqrt{5}-6)^2}-\sqrt{(\sqrt{5}+6)^2}`

`=|\sqrt{5}-6|-|\sqrt{5}+6|`

`=6-\sqrt{5}-6-\sqrt{5}`

`=-2\sqrt{5}`