Answer:
The answer is 3.
Explanation:
Factors of 18:
1, 2, 3, 6, 9, 18.
Factors of 21:
1, 3, 7.
The highest number that both sets contain is 3, so the GCF will be 3.
The GCF of 21 and 18 would be 3
Step-by-step explanation:
1, 3, 6, 9, 18
1, 3, 7
The only common factors between the 2 are 1 and 3 but you want the greatest so you choose 3.
Hope this helps! :)
