The domain of the function is the values of x for which the function is real and defined.
To find the domain, the only way that the function will be real is when the value of 6+ 5x is ≥ 0
Since
6 + 5x ≥ 0
Solve for x
6 + 5x ≥0
subtract 6 from both-side
5x ≥- 6
Divide both-side by 5
Hence the domain of f in interval notain is;