L3

07-22-2009, 06:52 AM

I'm very confused by factoring. I just can't remember how to do it, and I can't find any site online that will help me. In the math lesson I'm reading at the moment it factors x[sup:360hykfh]3[/sup:360hykfh] - 4 * x into (x + 2) * x * (x - 2). And Ijust don't see how it gets there and I've looked for math sites that would explain it to me and still just don't get it. I can see that, x[sup:360hykfh]3[/sup:360hykfh] - 4x you could factor x and get

(x[sup:360hykfh]2[/sup:360hykfh] - 4) * x but I don't understand how you get (x + 2) and (x - 2).

I mean I would think that x + 2 * x - 2 would get you x[sup:360hykfh]2[/sup:360hykfh] - 4 (though my calculator for some reason when I type that in, gives me -3 * x which doesn't really make sense to me, and I expect that answer might be due to the way I'm writing the question, I've never really figured out this calulator. And when I I try it on paper, using FOIL on (x + 2 )* (x - 2) I do get x[sup:360hykfh]2[/sup:360hykfh] - 4.) So I can see how you get from (x + 2 )* (x - 2) to x[sup:360hykfh]2[/sup:360hykfh] - 4 but not the other way around.

I really have tried to find an explanation online, and I know it's clearly that I just don't understand factoring, but I don't know where I'm going wrong, or what to look for.

(x[sup:360hykfh]2[/sup:360hykfh] - 4) * x but I don't understand how you get (x + 2) and (x - 2).

I mean I would think that x + 2 * x - 2 would get you x[sup:360hykfh]2[/sup:360hykfh] - 4 (though my calculator for some reason when I type that in, gives me -3 * x which doesn't really make sense to me, and I expect that answer might be due to the way I'm writing the question, I've never really figured out this calulator. And when I I try it on paper, using FOIL on (x + 2 )* (x - 2) I do get x[sup:360hykfh]2[/sup:360hykfh] - 4.) So I can see how you get from (x + 2 )* (x - 2) to x[sup:360hykfh]2[/sup:360hykfh] - 4 but not the other way around.

I really have tried to find an explanation online, and I know it's clearly that I just don't understand factoring, but I don't know where I'm going wrong, or what to look for.