 ## How to find the Least Common Multiple of 42 and 49?

On this page below, we'll use the Prime Factorisation, and the List of Multiples method to find out the LCM of 42 and 49.

Follow the steps below, and let's calculate the LCM of 42 and 49.

### Method 1 - Prime factorization

#### Step 1: Create a list of all the prime factors of the numbers 42 and 49:

##### Prime factors of 42

The prime factors of 42 are 2, 3 and 7. Prime factorization of 42 in exponential form is:

42 = 21x31x71

##### Prime factors of 49

The prime factors of 49 are 7 and 7. Prime factorization of 49 in exponential form is:

49 = 72

21, 31, 72

21x31x72=294

#### Step 4: The result:

As seen on the calculation above, we have now obtained the LCM of 42 and 49.

The Least Common Multiple of 42 and 49 is 294.

### Method 2 - List of Multiples

Find and list multiples of each number until the first common multiple is found. This is the lowest common multiple.

#### Multiples of 42:

42, 84, 126, 168, 210, 252, 294, 336, 378, 420

#### Multiples of 49:

49, 98, 147, 196, 245, 294, 343, 392, 441

#### Therefore,

LCM(42, 49) = 294