Dividing Polynomials AND Factoring Polynomials

Hi everyone!

I had a few questions regarding polynomials.

1) I am confused about dividing variables. If you have an x/x is that still x? or do they cancel each other out? For example 4x/2x = 2x or 2?

Also what if one has a square? 4xsquared/2x is that 2x?

What if both have squares?

2) Common Factoring

Is there a simple way to find the greatest common factor in a set of polynomials?

12x + 18y GCF= 6 correct?

2mn-n GCF= n?

= 2(2mn-n)? when you divide the terms by n is this what i should get? This is kinda of where my first question comes in.

Thanks so much!

I really appreciate the help!