Answer:
2
Step-by-step explanation:
The greatest common factor of whole numbers is the largest number that is a factor of all numbers. That is, it is the largest number that can divide all numbers.
In this case, the largest number that divide all the numbers is 2, who can divide 4, 18 and 12.
So:
[tex](4k, 18k^{4} ,12)= 2(2k,9k^{4} , 6)[/tex]
