Answer:
1, 2, 3, 6
Explanation:
This questions is asking the GCF of 42 and 90. To find them, we have to find all their factors.
42 90
1, 42 1, 90
2, 21 2, 45
3, 14 3, 30
6, 7 5, 18
6, 15
9, 10
Now we find the numbers that match up.
They both share 1, 2, 3, and 6 thus this is our answer