Can someone explain the basics of inequalities to me. I'm having trouble with the easiest of questions, just because the signs. For example: $\displaystyle x^3-4x^2+x+6<0\quad \Rightarrow (x+1)(x-2)(x-3)<0$ From here I have no idea what I'm doing. Can someone explain to me what to do after this point? I know it is something to do with negatives and positives. If someone could explain that to me I'd probably understand these a lot more. Thats my biggest issue.