Đáp án:
`d)sqrt{4-2sqrt3}-sqrt3`
`=sqrt{3-2sqrt3+1}-sqrt3`
`=sqrt{(sqrt3-1)^2}-sqrt3`
`=sqrt3-1-sqrt3=-1`
`e)sqrt{23+8sqrt7}-sqrt7`
`=sqrt{16+2.4.sqrt7+7}-sqrt7`
`=sqrt{(4+sqrt7)^2}-sqrt7`
`=4+sqrt7-sqrt7=4`
`f)2sqrt2(sqrt3-2)+(1+2sqrt2)^2-2sqrt6`
`=2sqrt6-4sqrt2+8+4sqrt2+1-2sqrt6`
`=(4sqrt2-4sqrt2)+(2sqrt6-2sqrt6)+9=9`