Question

What can you say about sets A and B if you know that.
1)A U B = A?

2)A ¿ B = A?

3)A - B = A?

Answer 1

1. A ⊇ B , B is a subset of A

2. not familiar with the operator ¿ in sets

3. Did not know that "-" was an operator with sets

Answer 2

I assume 2) is intersection
If the intersection of A and B = A, then A is a subset of B.

A-B is the members of A that are not in B. If that is equal to A, then B is empty.

Answer 3

Hmmm. On that last one, A-B=A means that A and B are disjoint, or B is empty.