Muddiest Point

As of right now, I would defibetly have to say that I am super confused on factoring the equations so we can then graph them.  The simple ones like f(x)=9x^2-25 I've got down, as well as simply knowing how to draw a graph and what it's approximate shape will look like when given the x intercepts.  Those rules and equations for the perfect cubes and square roots just confuse me, and I don't know what you put in as A and what's B.  I tried practicing some this weekend, but I just didn't get it.