first break both numbers down into prime factors
21 = 3x7
54 = 2x3x3x3
2x3x3x3x7=54x7 = 378
The LCM is 756.
378
The LCM is: 54
LCM = 54
The LCM is: 54
The LCM of 9, 18, and 54 is 54 the answer is 54
The LCM is: 54
The LCM is: 54
The LCM is 54.
The LCM is 54.
The LCM is: 270
The LCM is 108.