What is the least common multiple of 9, 18 , and 21?

1 Answer
MeneerNask
Apr 7, 2016

We first factor each of them into primes:

Explanation:

9=3xx3
18=2xx3xx3
21=3xx7

Now we take all prime factors to their highest degree that we find in the numbers, so we have one 2, two 3's and one 7:

Answer:
2xx3xx3xx7=126

Check :
126div9=14=2xx7
126div18=7
126div21=6=2xx3
And there is no common factor between the three of them.

Related questions
See all questions in Least Common Multiple
Impact of this question
14666 views around the world
You can reuse this answer
Creative Commons License