LCM for 42 and 28
What's the Least Common Multiple (LCM) of 42 and 28?
(Eighty-four)
Finding LCM for 42 and 28 using GCF's of these numbers
The first method to find LCM for numbers 42 and 28 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:
LCM = (Number1 × Number2) ÷ GCF
GCF of numbers 42 and 28 is 14, so
LCM = (42 × 28) ÷ 14
LCM = 1176 ÷ 14
LCM = 84
Finding LCM for 42 and 28 by Listing Multiples
The second method to find LCM for numbers 42 and 28 is to list out the common multiples for both nubmers and pick the first which matching:
Multiples of 42: 42, 84, 126, 168
Multiples of 28: 28, 56, 84, 112, 140
So the LCM for 42 and 28 is 84
Finding LCM for 42 and 28 by Prime Factorization
Another method to find LCM for numbers 42 and 28 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:
All Prime Factors of 42: 2, 3, 7 (exponent form: 21, 31, 71)
All Prime Factors of 28: 2, 2, 7 (exponent form: 22, 71)
22 × 31 × 71 = 84
Related Calculations
See Also
- Greatest Common Factor - Find the Greatest Common Factor (GCF) of two numbers
<a href="https://calculat.io/en/number/least-common-multiple-lcm-of/42--28">What is the LCM of 42 and 28? - Calculatio</a>
LCM Table
About "Least Common Multiple" Calculator
Least Common Multiple (LCM) also known as the Lowest Common Multiple or Smallest Common Multiple of 2 numbers - it is the smallest positive integer that is divisible by both numbers