Answer:
The lcm is 84
Step-by-step explanation:
3: 3,6,9,12,15,18,21,24,27,30,33,36,39,41,44,47.........84
4: 4,8,12,16,20,24,28,32,36,40,44........84
7: 7,14,21,28,35,42.......84
