The first function cannot have a denominator = 0
So.....the domain of this function is (-inf, 0) U (0,inf)
For the second function the function under the root cannot be < 0
So 5x - 11 = 0
5x = 11
x = 11/5
So....the domain for this function is [ 11/5 , inf )
The domain is the most restrictive domain = the second one = [ 11/5, inf)