6n^2 -18n-18 = 6 subtract 6 from both sides
6n^2 - 18n - 24 = 0 divide each term by 6
n^2 - 3n - 4 = 0
We need two terms that add to -3 and multiply to - 4
-4 and 1 seem to do the trick....so...
(n - 4) ( n + 1) = 0
Either
n - 4 = 0 or n + 1 =
n = 4 n = -1
