Solution: The LCM of 139 and 69 is 9591
Methods
How to find the LCM of 139 and 69 using Prime Factorization
One way to find the LCM of 139 and 69 is to start by comparing the prime factorization of each number. To find the prime factorization, you can follow the instructions for each number here:
What are the Factors of 139?
What are the Factors of 69?
Here is the prime factorization of 139:
13
9
1
139^1
13 9 1
And this is the prime factorization of 69:
3
1
×
2
3
1
3^1 × 23^1
3 1 × 2 3 1
When you compare the prime factorization of these two numbers, you want to look for the highest power that each prime factor is raised to. In this case, there are these prime factors to consider: 139, 3, 23
3
1
×
2
3
1
×
13
9
1
=
9591
3^1 × 23^1 × 139^1 = 9591
3 1 × 2 3 1 × 13 9 1 = 9591
Through this we see that the LCM of 139 and 69 is 9591.
How to Find the LCM of 139 and 69 by Listing Common Multiples
The first step to this method of finding the Least Common Multiple of 139 and 69 is to begin to list a few multiples for each number. If you need a refresher on how to find the multiples of these numbers, you can see the walkthroughs in the links below for each number.
Let’s take a look at the multiples for each of these numbers, 139 and 69:
What are the Multiples of 139?
What are the Multiples of 69?
Let’s take a look at the first 10 multiples for each of these numbers, 139 and 69:
First 10 Multiples of 139: 139, 278, 417, 556, 695, 834, 973, 1112, 1251, 1390
First 10 Multiples of 69: 69, 138, 207, 276, 345, 414, 483, 552, 621, 690
You can continue to list out the multiples of these numbers as long as needed to find a match. Once you do find a match, or several matches, the smallest of these matches would be the Least Common Multiple. For instance, the first matching multiple(s) of 139 and 69 are 9591, 19182, 28773. Because 9591 is the smallest, it is the least common multiple.
The LCM of 139 and 69 is 9591.
Find the LCM of Other Number Pairs
Want more practice? Try some of these other LCM problems:
What is the LCM of 41 and 7?
What is the LCM of 56 and 121?
What is the LCM of 79 and 68?
What is the LCM of 28 and 37?
What is the LCM of 110 and 51?