Answer :
[tex] 6n^2-18n-18=6 \\
6n^2-18n-24=0\\
n^2-3n-4=0\\
n^2+n-4n-4=0\\
n(n+1)-4(n+1)=0\\
(n-4)(n+1)=0\\
n=4 \vee n=-1[/tex]
[tex]6n^{2}-18n-18=6 \\ 6n^{2}-18n-24=0 \\ 6(n^{2}-3n-4)=0 \\ 6(n-4)(n+1)=0 \\ \boxed{n=4\ and\ -1}[/tex]
