Answer:
4y
Step-by-step explanation:
To find the greatest common factor of 2 numbers, factor both of the numbers:
4: 1, 2, 4
12: 1, 2, 3, 4, 6, 12
The greatest factor here in both of these lists is 4. These numbers also both have a factor of y, so you multiply those together and get 4y.
[tex]4\times y=4y[/tex]
