Solution: The LCM of 71 and 51 is 3621
Methods
How to find the LCM of 71 and 51 using Prime Factorization
One way to find the LCM of 71 and 51 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 71?
What are the Factors of 51?
Here is the prime factorization of 71:
7
1
1
71^1
7 1 1
And this is the prime factorization of 51:
3
1
×
1
7
1
3^1 × 17^1
3 1 × 1 7 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: 71, 3, 17
3
1
×
1
7
1
×
7
1
1
=
3621
3^1 × 17^1 × 71^1 = 3621
3 1 × 1 7 1 × 7 1 1 = 3621
Through this we see that the LCM of 71 and 51 is 3621.
How to Find the LCM of 71 and 51 by Listing Common Multiples
The first step to this method of finding the Least Common Multiple of 71 and 51 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, 71 and 51:
What are the Multiples of 71?
What are the Multiples of 51?
Let’s take a look at the first 10 multiples for each of these numbers, 71 and 51:
First 10 Multiples of 71: 71, 142, 213, 284, 355, 426, 497, 568, 639, 710
First 10 Multiples of 51: 51, 102, 153, 204, 255, 306, 357, 408, 459, 510
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 71 and 51 are 3621, 7242, 10863. Because 3621 is the smallest, it is the least common multiple.
The LCM of 71 and 51 is 3621.
Find the LCM of Other Number Pairs
Want more practice? Try some of these other LCM problems:
What is the LCM of 17 and 124?
What is the LCM of 82 and 123?
What is the LCM of 140 and 5?
What is the LCM of 54 and 122?
What is the LCM of 130 and 25?