I need to find the domain of

f(x) = (3x+3)/ (x^2 -3).

I keep getting (U SQUARE Root of 3 and - Square root of 3 U ) Does that mean that the answer is all real numbers?
I know that x can not=3, What am I doing wrong? Thanks.

x² cannot be 3, so

x cannot be √3 nor -√3.

The domain is therefore
R - (√3∪-√3)