Answer:
12
Step-by-step explanation:
First lets list all the factors of these numbers
72: 1,2 3,4,6,8,9,12,18,24,36,72
84: 1 , 2 , 3 ,4 , 6 , 7 , 12 , 14 , 21 , 28 , 42 , 84
Now lets find the biggest number that is a factor of both 84 and 72
as we can see the highest number that is the factor of both 84 and 72 is 12
12 is the hcf
