Hi all,

I've been struggling a little with my algebra so during the summer break I've been working through the book Algebra Demystified and it's really helping.

But I've come across a question half way through that I can't solve, I'm not sure how to tackle it, the question and answer are

$\displaystyle x^{3}+5x^{2}-x-5=(x-1)(x+1)(x+5)$

Any tips or a starting point would be greatly appreciated.

Thanks.