## Kitten_is_back one year ago For which operations is the set {–1, 1} closed? Choose all answers that are correct. A. addition B. subtraction C. multiplication D. division

1. anonymous

If I remember what these questions are about, C, and D are correct. $-1 \times 1 = -1$ $\dfrac{-1}{1} = -1$ Negative one is part of the set. Ergo, closed.

2. Kitten_is_back

so times and subtraction?

3. anonymous

Subtraction does not work, since you get 0, and that is not part of the set.

4. Kitten_is_back

okay so its a c or d we know its c what about addition?

5. anonymous

Actually we know it is both, C, and D. Any my bad, with addition we get zero, subtraction gives us -2, which is also not in the set.

6. Kitten_is_back

okay so its just c d?

7. anonymous

Addition: -1 + 1 = 0. Subtraction: -1 - 1 = -2

8. anonymous

Yes.

9. Kitten_is_back

so b c d?

10. anonymous

B gives -2, and the set is only {-1, 1} so no.

11. Kitten_is_back

okay M<# thans