# Math Help - Understanding this for factoring

1. ## Understanding this for factoring

Factor completly:
(3n-1)2 - (3n-1) - 72

What do you use to process this? If there is nothing to work with the -72? You can factor out (3n-1) correct? But still left with the -72?

2. ## Re: Understanding this for factoring

Originally Posted by Kibbygirl
Factor completly:
(3n-1)2 - (3n-1) - 72
$x^2-x-72=(x-9)(x+8)$. Let $x=3n-1.$