First you should find the gcm factor because that is the number we will place outside of the parentheses in order to distribute. The GCM of 12 and 80 is 4. So, we place 4 outside of the grouping symbol. Now, we have to form what will be inside of the parentheses. When we use distributive property, we take the inner number and multiply it by the outside number. So, that means if we have 12 the inner number should be 3 since 4*3=12. Now, we move onto the number 80. Same thing here. This time it's going to be 20 since 4*20=80
