,

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.

Since has no factors besides and .

is a prime number

Since has no factors besides and .

is a prime number

The LCM of is the result of multiplying all prime factors the greatest number of times they occur in either number.

Multiply by .

Find the LCM 3 , 7