if either or both of [tex][n][/tex] and [tex][n+8][/tex] are 0, i.e. if one or both of [tex]n[/tex] and [tex]n+8[/tex] are even. But both will be even if [tex]n[/tex] is even, and odd otherwise, so any even [tex]n[/tex] will be a solution, e.g. [tex]n=2[/tex].
