18 is not a prime number so no number can have 18 as a prime factor.
You can not factor prime numbers, that is why they are prime numbers
Use a factor tree. 18 9,2 3,3,2
The greatest prime factor of both numbers is 3
The common prime factors of 18 and 30 are 2 and 3.
3
All numbers have factors. Some factors are prime numbers. A prime factor is a factor that is a prime number. A common prime factor is a prime factor that appears on the list of factors of two or more given numbers.
The GCF of 18 and 49 is 1. These numbers are relatively prime
All nonzero numbers have factors. Some factors are prime numbers. 5 is a prime factor of 10.
18 is a factor (composite).
Numbers that are co-prime have no factors in common. Because 6 is a common factor of both 12 and 18, they are not co-prime, or prime to each other.
The 3 number that make the prime factorization of 18 are 2 x 3 x 3.