How Do We Add And Subtract Rational Expressions ?

To add and subtract rational expression, you have to first find a common denominator.

                                                    X-1                X-5        <------ Numerator
                                                  X +6                X+6       <------ Denominator
Lets take :

              u-v               6u -3v
              8v       +          8v 
 The first step in solving this is finding a common denominator. Since this rational expression already is in a common denominator, you don't have to worry about it.

Next you add or subtract the terms, according to what the question ask you. In this case, You add by adding like terms.

          So .....                  u + 6u = 7u   and  -1v-3v = -4v 
                Together the numerator is  7u-4v
                               the denominator is 8v.


NOW TRY THIS : 

                     7p+9z     -     3p+8z
                         9g                 9g