(1)

• "A - B" means the part of A where B is excluded.
• "B - A" means the part of B where A is excluded.

When we find (A - B) U (B - A), we actually go on finding the part as shown in the diagram.

(2)

We need to use set law in this case.

• A' U B' = (A ∩ B)'

This means that we find the region except for the common region of intersection of A and B.

{ Refer to the attachments, please! }