Respuesta :

The answer is 4830.

We find the LCM by finding the prime factorization of each number:
115 = 5(23)
138 = 2(3)(23)
161 = 7(23)

The GCF of all of these numbers is 23.  The LCM is the GCF multiplied by the other factors:
23(2)(3)(5)(7) = 4830