Help finding a common denominator

[Femme_physics]

Everything is attached. I spent some serious time trying to come up with one, but am flanking miserable. I even attached my latest attempt. Can anyone clue me or even just tell me what it is?

 

[SteamKing]

Find the common denominators on each side of the equals sign independently so that you can add the two fractions on each side together: you have A+B = C+D. You want to get E=F. Once you get E=F, you are able to cross multiply. On the left side of the original equation, factor the denominator (x^2-1) first.

 

[Borek]

Compare these two.

 

[Femme_physics]

Why do I need to compare them?

But nevermind, I got the answer by indeed factoring the first denominator to (x+1)(x-1)

Thanks a bunch :)!

 

[Borek]

If you would look at them it will become obvious by what do you have to multiply one to get the other. x is not the correct idea.