Với `n≥0;n\ne4`
`P=(\sqrtn+3)/(\sqrtn-2)-(\sqrtn-1)/(\sqrtn+2)+(4\sqrtn-4)/(4-n)`
`=(\sqrtn+3)/(\sqrtn-2)-(\sqrtn-1)/(\sqrtn+2)+(4-4\sqrtn)/(n-4)`
`=((\sqrtn+3)(\sqrtn+2)-(\sqrtn-1)(\sqrtn-2)+4-4\sqrtn)/((\sqrtn-2)(\sqrtn+2))`
`=((n+2\sqrtn+3\sqrtn+6)-(n-2\sqrtn-\sqrtn+2)+4-4\sqrtn)/((\sqrtn-2)(\sqrtn+2))`
`=((n+5\sqrtn+6)-(n-3\sqrtn+2)+4-4\sqrtn)/((\sqrtn-2)(\sqrtn+2))`
`=(n+5\sqrtn+6-n+3\sqrtn-2+4-4\sqrtn)/((\sqrtn-2)(\sqrtn+2))`
`=(4\sqrtn+8)/((\sqrtn-2)(\sqrtn+2))`
`=(4(\sqrtn+2))/((\sqrtn-2)(\sqrtn+2))`
`=4/(\sqrtn-2)`
Vậy với `n≥0;n\ne4` thì `P=4/(\sqrtn-2)`
