Remark
This is like using the distributive principle only you are going backwards. Instead of trying to remove brackets, you are trying to create them.
Solution
Since you want to take - 6 outside the brackets you should divide both terms by - 6
- 18a: - 18a/- 6 = 3a which is left inside the brackets.
-30: - 30/-6 = 5
- 6(3a + 5)
Answer
-6(3a + 5)
