Đáp án + Giải thích các bước giải:
`a)`
`\sqrt{28+10\sqrt{3}}`
`=\sqrt{25+2.5.\sqrt{3}+3}`
`=\sqrt{(5+\sqrt{3})^{2}}`
`=|5+\sqrt{3}|`
`=5+\sqrt{3}`
`b)`
`\sqrt{6-2\sqrt{5}}`
`=\sqrt{1-2.1.\sqrt{5}+5}`
`=\sqrt{(1-\sqrt{5})^{2}}`
`=|1-\sqrt{5}|`
`=\sqrt{5}-1`
`c)`
`\sqrt{12+6\sqrt{3}}+\sqrt{12-6\sqrt{3}}`
`=\sqrt{9+2.3.\sqrt{3}+3}+\sqrt{9-2.3.\sqrt{3}+3}`
`=\sqrt{(3+\sqrt{3})^{2}}+\sqrt{(3-\sqrt{3})^{2}}`
`=|3+\sqrt{3}|+|3-\sqrt{3}|`
`=3+\sqrt{3}+3-\sqrt{3}`
`=6`
