I feel silly for having to post this, but for the life of me I can't remember how to factor quadrinomials. My mother is taking an algebra class and was asking for my help. Shamefully, I couldn't figure out how to get the answer. I'd like to blame it on the fact that I haven't done this kind of math in well over 10 years, and that it's so late so my brain isn't working. So here I am posting to find out how to solve this problem because it's going to drive me crazy until I figure out what it is that I'm missing: x^3 + 4x^2+x -6 The answer is (x-1)(x+2)(x+3), but how do you get to that? I've tried various forms of grouping, but so far nothing has come up as a GCF for both groups. What am I forgetting?