Question 164694
It's simple enough, but zero is not what you have to worry about. 
The worry is when the denominator goes to zero because the function is then undefined. 
In this case, the function is undeined when x+6=0, or x=-6. 
The domain would then be all x except x=-6, or in interval notation,
({{{-infinity}}},{{{-6}}})U({{{-6}}},{{{infinity}}})