[Blindmath] Help factoring a crazy trinomial

[GianniP46]

Hi all,
I need help factoring X^4-2X^2-1

I am thinking that there is a way of re writing this as a four termed expression where the product of the first and last terms must equal the product of the two middle terms, but I am stuck :(
I know the answer is (X+1)(X-1)(X+1)(X-1)
Feeling very dumb, any help would be appreciated THANKS lol

Gian Pedulla
Giannip46 at earthlink.net

LETS GO METS!