Algebra
Find the least common multiple. 21, 28
Holt McDougal Larson Pre-Algebra Common Core Edition page 782 number 26
Holt McDougal Larson Pre-Algebra Common Core Edition page 782 number 26
First factor the numbers
21 3*7
28 7 *2*2
3*7*2*2
The LCM is the product of all the columns of factors
=3*7*2*2=84