Solution: The LCM of 87 and 89 is 7743
Methods
How to find the LCM of 87 and 89 using Prime Factorization
One way to find the LCM of 87 and 89 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 87?
What are the Factors of 89?
Here is the prime factorization of 87:
3
1
×
2
9
1
3^1 × 29^1
3 1 × 2 9 1
And this is the prime factorization of 89:
8
9
1
89^1
8 9 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: 3, 29, 89
3
1
×
2
9
1
×
8
9
1
=
7743
3^1 × 29^1 × 89^1 = 7743
3 1 × 2 9 1 × 8 9 1 = 7743
Through this we see that the LCM of 87 and 89 is 7743.
How to Find the LCM of 87 and 89 by Listing Common Multiples
The first step to this method of finding the Least Common Multiple of 87 and 89 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, 87 and 89:
What are the Multiples of 87?
What are the Multiples of 89?
Let’s take a look at the first 10 multiples for each of these numbers, 87 and 89:
First 10 Multiples of 87: 87, 174, 261, 348, 435, 522, 609, 696, 783, 870
First 10 Multiples of 89: 89, 178, 267, 356, 445, 534, 623, 712, 801, 890
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 87 and 89 are 7743, 15486, 23229. Because 7743 is the smallest, it is the least common multiple.
The LCM of 87 and 89 is 7743.
Find the LCM of Other Number Pairs
Want more practice? Try some of these other LCM problems:
What is the LCM of 75 and 126?
What is the LCM of 105 and 86?
What is the LCM of 122 and 66?
What is the LCM of 120 and 23?
What is the LCM of 76 and 18?