Posted by Jules on Friday, September 14, 2007 at 9:43pm.
I don't understand how to do this problem, can you please help me?
Given the functions f and g, determine the domain of f+g.
4. f(x)= 2x/(x3) g(x)=3/(x+6)

Domains of Functions  drwls, Saturday, September 15, 2007 at 9:52am
That would be the set of real numbers x that result in real values for f + g
For f(x) by itself, the domain is all numbers except 3. For g(x), the domain is all numbers except 6.
For f + g, the domain is all numbers from infinity to +infinity except 6 and 3. 
Domains of Functions  drwls, Saturday, September 15, 2007 at 10:13am
For further reading I suggest
http://www.analyzemath.com/DomainRange/DomainRange.html