Answer:
1, 2, 3, 6
Step-by-step explanation:
This questions is asking the GCF of 42 and 90. To find them, we have to find all their factors.
42 Â Â Â Â Â Â Â Â Â Â Â 90
1, 42 Â Â Â Â Â Â Â Â Â 1, 90
2, 21 Â Â Â Â Â Â Â Â Â 2, 45
3, 14 Â Â Â Â Â Â Â Â Â 3, 30
6, 7 Â Â Â Â Â Â Â Â Â 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