# Math Help - Basic Alg Help

1. ## Basic Alg Help

Factor out the GCF x(3x-1) + 5(3x-1)
*The GCF is 3x-1 so we'll divide both terms by the GCF

x(3x-1) + 5(3x-1)
-----------------------------------------------
3x-1

*cancel the 3x-1 on the x part then the 3x-1 on the 5 part leaving:

x+5
The complete answer then is (3x-1) (x+5)..

I'm confused because where did 3x-1 came from I mean besides the fact that it's the GCF..Is there a rule that states that the "other set of term" will be the GCF???plss help me...

2. Originally Posted by quantumie

Factor out the GCF x(3x-1) + 5(3x-1)
*The GCF is 3x-1 so we'll divide both terms by the GCF

x(3x-1) + 5(3x-1)
-----------------------------------------------
3x-1

*cancel the 3x-1 on the x part then the 3x-1 on the 5 part leaving:

x+5
The complete answer then is (3x-1) (x+5)..

I'm confused because where did 3x-1 came from I mean besides the fact that it's the GCF..Is there a rule that states that the "other set of term" will be the GCF???plss help me...
Let's just simplify it a bit. Imagine you had:
xa + 5a
GCF is a, so you "factorise" it out - you can't just "cancel" it out.
So:
xa + 5a = a(x+5)

You can't say that xa + 5a = x+5 because it doesn't.
Replace a with 3x-1 in your problem.

3. tnx a lot =)