Setting the denominator to zero will break up the domain into 5 parts.
 2x2 + x - 6  =  0     --->     (2x - 3)(x + 2)  =  0     --->     x = 1.5  and  x = -2.
 The five parts are:  1)  the region below x = -2
                                 2)  x = -2                                                              <--- at this point there is a break in the graph
                                 3)  the region between x = -2 and x = 1.5
                                 4)  x = 1.5                                                            <--- at this point there is a break in the graph
                                 5)  the region above x = 1.5
  
 Choose a number in the region below x = -2  ---   any number, I chose -5.  Place this number into the problem to see
 if the answer is above 0 or below 0. It's above 0, so this region "works".
  
 Choose a number in the region between x = -2 and x = 1.5  ---   any number, I chose 0. Place this number into the
 problem to see if the answer is above 0 or below 0. It's below 0, so this region "doesn't work".
  
 Choose a number in the region above x = 1.5  ---   any number, I chose 5.  Place this number into the problem to see
 if the answer is above 0 or below 0. It's above 0, so this region "works".
  
 So, the answer is:  (-infinity, -2)  union  (1.5, infinity)