Question 6096
Common factors are those factors which are the same for two or more numbers

1) 18 - 2, 3, 6, 9, 18
2) 30 - 2, 3, 5, 6, 10, 15, 30
3) 17 - is a prime number 1 and itself 17
4) -8 - I don't know why you have a negative, but the factors are 2, 4, 8

Hope this helps you