Factoring Cubic Equations I’ve been trying to figure out how to factor cubic equations by studying a few worksheets online such as the one here and was wondering is there any generalized way of factoring these types of equations or do we just need to remember a bunch of different cases. 
For example, how would you factor the following: 

$x^3 – 7x^2 +7x + 15$

I'm have trouble factoring equations such as these without obvious factors. 

$x^3-7x^2+7x+15=(x+1)(x-3)(x-5)$
