Q:

What is the LCM of 18 and 126?

Accepted Solution

A:
Solution: The LCM of 18 and 126 is 126 Methods How to find the LCM of 18 and 126 using Prime Factorization One way to find the LCM of 18 and 126 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 18? What are the Factors of 126? Here is the prime factorization of 18: 2 1 × 3 2 2^1 × 3^2 2 1 × 3 2 And this is the prime factorization of 126: 2 1 × 3 2 × 7 1 2^1 × 3^2 × 7^1 2 1 × 3 2 × 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: 2, 3, 7 2 1 × 3 2 × 7 1 = 126 2^1 × 3^2 × 7^1 = 126 2 1 × 3 2 × 7 1 = 126 Through this we see that the LCM of 18 and 126 is 126. How to Find the LCM of 18 and 126 by Listing Common Multiples The first step to this method of finding the Least Common Multiple of 18 and 126 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, 18 and 126: What are the Multiples of 18? What are the Multiples of 126? Let’s take a look at the first 10 multiples for each of these numbers, 18 and 126: First 10 Multiples of 18: 18, 36, 54, 72, 90, 108, 126, 144, 162, 180 First 10 Multiples of 126: 126, 252, 378, 504, 630, 756, 882, 1008, 1134, 1260 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 18 and 126 are 126, 252, 378. Because 126 is the smallest, it is the least common multiple. The LCM of 18 and 126 is 126. Find the LCM of Other Number Pairs Want more practice? Try some of these other LCM problems: What is the LCM of 61 and 17? What is the LCM of 29 and 4? What is the LCM of 74 and 83? What is the LCM of 112 and 140? What is the LCM of 52 and 10?