`\text{Đáp án:}`
`=1`
`\text{Giải thích các bước giải:}`
`\sqrt{\sqrt{5}-\sqrt{3-\sqrt{29-12\sqrt{5}}}}`
`=\sqrt{\sqrt{5}-\sqrt{3-\sqrt{(2\sqrt{5})^2-2\cdot 2\sqrt{5}\cdot 3+9}}}`
`=\sqrt{\sqrt{5}-\sqrt{3-\sqrt{(2\sqrt{5}-3)^2}}}`
`=\sqrt{\sqrt{5}-\sqrt{3-|2\sqrt{5}-3|}}`
`=\sqrt{\sqrt{5}-\sqrt{3-(2\sqrt{5}-3)}}`
`=\sqrt{\sqrt{5}-\sqrt{3-2\sqrt{5}+3}`
`=\sqrt{\sqrt{5}-\sqrt{6-2\sqrt{5}}`
`=\sqrt{\sqrt{5}-\sqrt{5-2\sqrt{5}+1}`
`=\sqrt{\sqrt{5}-\sqrt{(\sqrt{5}-1)^2}`
`=\sqrt{\sqrt{5}-|\sqrt{5}-1|}`
`=\sqrt{\sqrt{5}-\sqrt{5}+1}`
`=\sqrt{1}`
`=1`
