Answer:
6, 6w, 3w, z and w.
Explanation:
The common factors are those values that can divide 18w and 30wz perfectly.
Take a look at 6, 6 can divide both perfectly to give 3w and 5wz respectively.
We move on to 6w, this can also work perfectly to yield 3 and 5z.
6xz is not a factor as both values do not contain any x term.
3z is not a factor. Although 30wz has a z term, 18w does not.
3w is a factor as it can give 10z and 6 when used to divide the terms.
Z is not a factor as the 18w term does not contain a z term.
10w is not a term as it can not divide 18w perfectly
w is a term as it can divide both 18w and 30wz perfectly to yield 18 and 30z respectively.