Examples
5656 , 812812 , 4747
Step 1
Step 1.1
Factor 44 out of 88.
56,4(2)12,4756,4(2)12,47
Step 1.2
Cancel the common factors.
Step 1.2.1
Factor 44 out of 1212.
56,4⋅24⋅3,4756,4⋅24⋅3,47
Step 1.2.2
Cancel the common factor.
56,4⋅24⋅3,47
Step 1.2.3
Rewrite the expression.
56,23,47
56,23,47
56,23,47
Step 2
To find the LCM for a list of fractions such as LCM(ab,cd) using GCF:
1. Find the LCM of a and c.
2. Find the GCF of b and d.
3. LCM(ab,cd)=LCM(a,c)GCF(b,d).
Step 3
Step 3.1
The LCM is the smallest positive number that all of the numbers divide into evenly.
1. List the prime factors of each number.
2. Multiply each factor the greatest number of times it occurs in either number.
Step 3.2
Since 5 has no factors besides 1 and 5.
5 is a prime number
Step 3.3
Since 2 has no factors besides 1 and 2.
2 is a prime number
Step 3.4
4 has factors of 2 and 2.
2⋅2
Step 3.5
The LCM of 5,2,4 is the result of multiplying all prime factors the greatest number of times they occur in either number.
2⋅2⋅5
Step 3.6
Multiply 2⋅2⋅5.
Step 3.6.1
Multiply 2 by 2.
4⋅5
Step 3.6.2
Multiply 4 by 5.
20
20
20
Step 4
Find the GCF of the denominators 6,3,7.
GCF(6,3,7)=1
Step 5
Divide 20 by 1.
20