The statement is not always true.
For Example...
The LCM of 6 and 8 is not the product of the two numbers
6*8= 48
48 is not the LEAST common multiple
Multiples of 6 are...
6,12,18,24,30,36,42,48...
Multiples of 8 are....
8,16,24,32,40,48...
The least common multiple is 24 not 48 even though they are both common multiples.