Respuesta :
Step-by-step explanation:
The lcm of first question is 630 and second is 840
Answer:
LCM of 15,18,21: 630
LCM of 56,84,140: 840
Step-by-step explanation:
The right method is to list all the multiples of the number and circle the least common ones. In this way you will get your answer for any LCM question!