`(3\sqrt{3}+3)(\sqrt{3}-1)-(2\sqrt{2}+\sqrt{3})^2`
`=3\sqrt{3}.\sqrt{3}-3\sqrt{3}.1+3.\sqrt{3}-3.1-[(2\sqrt{2})^2+2.2\sqrt{2}.\sqrt{3}+(\sqrt{3})^2]`
`=3.3-3\sqrt{3}+3\sqrt{3}-3-(8+4\sqrt{6}+3)`
`=9-3\sqrt{3}+3\sqrt{3}-3-8-4\sqrt{6}-3`
`=(3\sqrt{3}-3\sqrt{3})+(9-3-8-3)-4\sqrt{6}`
`=-5-4\sqrt{6}`