The expanded form of LCM is Lease common multiple which means find the common multiple with least value for a given set of numbers. This can be done by using either prime numbers or by using composite numbers or with a combination of prime numbers and composite numbers. The LCM can also be written with exponents.
Steps to Find the Lcm Using Prime Factorization:
Step 1: Write the given set of numbers.
Step 2: Take the first number from the given set.
Step 3: Write the number with the multiples of prime numbers.
Step 4: Repeat step 2 and Step 3 for all the numbers in a given set.
Step 5: Choose the highest exponent term form all and multiply it to get LCM of given numbers.
Example Problems – Lcm Using Prime Factorization:
Example 1- LCM using prime factorization:
Find the LCM of 30 and 10.
Solution:
The given numbers are 30 and 10.
First it needs to find the prime factors of 30.
30 = 2*15
= 2 * 3 * 5
The prime factors of 30 are 21, 31 and 51.
Next it needs to find the prime factors of 10.
10 = 2 * 5.
The prime factors of 10 are 21 and 51.
The highest exponent of all terms is 21, 31 and 51.
The LCM of 30 and 10 is 2 * 3* 5 `=>` 30.
My forthcoming post is on prime factorization algorithm, adding and subtracting rational expressions with unlike denominators will give you more understanding about Algebra
Example 2- LCM using prime factorization:
Find the LCM of 42 and 60.
Solution:
The given numbers are 42 and 60.
First it needs to find the prime factors of 42.
42 = 2*21
= 2 * 3 * 7
The prime factors of 30 are 21, 31 and 71.
Next it needs to find the prime factors of 60.
60 = 2 * 30
= 2 * 2 * 15
= 2* 2 * 3* 5
The prime factors of 10 is 22 , 31 and 51.
The highest exponent of all terms is 22, 31, 51 and 71.
The LCM of 30 and 10 is 22 * 3* 5* 7 `=>` 420.
Example 3- LCM using prime factorization:
Find the LCM of 50 and 100.
Solution:
The given numbers are 50 and 100.
First it needs to find the prime factors of 50.
50 = 2*25
= 2 * 5 * 5
The prime factors of 50 are 21 and 52
Next it needs to find the prime factors of 60.
100 = 2 * 50
= 2 * 2 * 25
= 2* 2 * 5* 5
The prime factors of 10 is 22 and 52
The highest exponent of all terms is 22 and 52
The LCM of 30 and 10 is 22 * 52 `=>` 100