Solution: The LCM of 42 and 29 is 1218
Methods
How to find the LCM of 42 and 29 using Prime Factorization
One way to find the LCM of 42 and 29 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 42?
What are the Factors of 29?
Here is the prime factorization of 42:
2
1
×
3
1
×
7
1
2^1 × 3^1 × 7^1
2 1 × 3 1 × 7 1
And this is the prime factorization of 29:
2
9
1
29^1
2 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: 2, 3, 7, 29
2
1
×
3
1
×
7
1
×
2
9
1
=
1218
2^1 × 3^1 × 7^1 × 29^1 = 1218
2 1 × 3 1 × 7 1 × 2 9 1 = 1218
Through this we see that the LCM of 42 and 29 is 1218.
How to Find the LCM of 42 and 29 by Listing Common Multiples
The first step to this method of finding the Least Common Multiple of 42 and 29 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, 42 and 29:
What are the Multiples of 42?
What are the Multiples of 29?
Let’s take a look at the first 10 multiples for each of these numbers, 42 and 29:
First 10 Multiples of 42: 42, 84, 126, 168, 210, 252, 294, 336, 378, 420
First 10 Multiples of 29: 29, 58, 87, 116, 145, 174, 203, 232, 261, 290
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 42 and 29 are 1218, 2436, 3654. Because 1218 is the smallest, it is the least common multiple.
The LCM of 42 and 29 is 1218.
Find the LCM of Other Number Pairs
Want more practice? Try some of these other LCM problems:
What is the LCM of 32 and 13?
What is the LCM of 3 and 51?
What is the LCM of 144 and 71?
What is the LCM of 68 and 56?
What is the LCM of 31 and 148?