Answer:
It all depends.
Step-by-step explanation:
It depends on what you are trying to do, and what you want to solve for. If you are trying to distribute the 3 into 2, you would place the parentheses around the 2. I hope I was able to help, but there is not much that I can do without more clear instructions!
Step-by-step explanation:

219+159≤x≤369+309
The answer can then be simplified to
378≤x≤678
Answer:
18-20=-2
Step-by-step explanation:
18-20=-2
18+(-20)=-2