LCM( 72, 57 ) = 1368
Step 1: Write down factorisation of each number:
72 = 2 · 2 · 2 · 3 · 3
57 = 3 · 19
Step 2 : Match primes vertically:
72 | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | ||
57 | = | 3 | · | 19 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
72 | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | ||||
57 | = | 3 | · | 19 | ||||||||||
LCM | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | · | 19 | = | 1368 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.