Solve Fractions Question Homework: Methodology Needed

[GreenMind]

Homework Statement

http://server6.theimagehosting.com/image.php?img=fractions.JPG
Can someone please give me the methodology/rules for this to happen?

Homework Equations

N/A

The Attempt at a Solution

I know there is nothing you can factor out here so I am confused as to how this result is possible.

Any help appreciated.

 

[hage567]

Start by dividing the numerator through by R^4. See what you think after that. Then look at the denominator. I don't see where the negative sign in front ends up going to though.

 

[GreenMind]

Thank you, Hage567 that helped me. The negative sign I just forgot when I typed in it really should be there.

I forgot that that you don't need to divide the whole equation just the denominator or numerator when trying to cancel out.