How to Combine and Simplify Rational Expressions

Question

I have this problem that it says to combine and simpify even though my textbook doesn't show you how to combine in the first place. The problem is this:

4w^2/4w^2z + 6wz^2 - 9z^2/4w^2z + 6wz^2

Thanks for your help!

Answer 1

4w^2                          9z^2

--------   +  6wz^2  -   ------       + 6wz^2

4w^2z                        4w^2z  

   1              9z^2

-------  +  ---------   + 12wz^2

   z            4w^2z

get a common denominator of 4w^2z

4w^2 + 9z^2 + 12w^3z^2

--------------------------------

                 4w^2z

 

Answer 2

(3x^3-4y^2)^3