Goldbach's conjecture says that every even number greater than
two can be expressed as the sum of 2 primes. If 30 could not be
expressed as the sum of two primes, then this would disprove the
conjecture. As it is, 30 can be expressed as the sum of two primes.
You can express it as 11+19. Thus, Goldbach's conjecture holds in
this case.