Question 1038402:  for what values of the variable x is the rational expression undefined : 8/(x+2) 
 Answer by jim_thompson5910(35256)      (Show Source): 
You can  put this solution on YOUR website! We CANNOT divide by zero. Something like 8/0 is undefined.  
Think of a house built upon a foundation of nothing. It would collapse.  
That's how I remember that 0 cannot be in the denominator.
 
 
So because 0 can't be in the denominator, this means x+2 cannot be zero.
 
 
If x+2 were zero, then solving x+2 = 0 for x gives x = -2
 
 
This means if x = -2 then x+2 is zero.
 
 
------------------------------------------------------------------------
 
 
If x = -2, then the rational expression is undefined because this leads to a division by zero error. Any other real number is allowed for x.  
  | 
 
  
 
 |   
 
 |