rút gọn....................................

`\sqrt{( \sqrt{2} - 3 )^2 } . \sqrt{11 + 6\sqrt{2} }`

`= | \sqrt{2} - 3 | . \sqrt{3^2 + 2 . 3 . \sqrt{2} + ( \sqrt{2} )^2 }`

`= ( 3 - \sqrt{2} ) . \sqrt{( 3 + \sqrt{2} )^2 }`

`= ( 3 - \sqrt{2} ) . | 3 + \sqrt{2} |`

`= ( 3 - \sqrt{2} ). ( 3 + \sqrt{2} )`

`= 3^2 - ( \sqrt{2} )^2`

`= 9 - 2`

`= 7`