RATIONAL FUNCTIONS
Rational functions are those which contain a numerator and denominator, and the denominator must not equal 0.
A rational function is one in which one term is divided by another.

  Examples of rational functions:
                                                                                                                      
         
x+2      Can not be simplified. Can also be represented as (x+2)(x-5)^ -1
          x-5

          x^2 -5x + 6   = (x-2)(x-3)    =  x-2
                x-3                     x-3

   Always try to factor the numerator first and then simplify, if possible.

    Let's try something more complex:

    
(x+5)(x-4)(x+3) = x + 5     Two terms cancel each other out.
     (x-4)(x+3)   

     Let's go one step further:

    
x+2 + x-5   =  (x+2)(x-6) + (x+7)(x-5)    =  x^2 -4x -12 + x^2+2x-35
     x+7     x-6                  (x+7)(x-6)                              x^2 +x-42
                                                                      
                                                                         =     
2x^2 -2x - 47   
                                                                                     x^2+x-42


   Sometimes the solution is not so simple.

   One more example:

    
x+1 - x-1 + 3     =   7(x+1)-4(x-1) + 1.5
     4       7      2                  28
                                   
                                    
7x+7-4x+4   + 1.5
                                            28
                                      
7x +7 -4x+4 +(28)(1.5)
                                                       28
                                       =    
3x +53                                   
                                                  28

     Another example:

                                      
2x    + 9x   + 3x    =   14x    =   2x
                                        7         7        7            7

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