Question

For which operations is the set {–1, 1} closed?

Choose all answers that are correct.

A.
addition

B.
subtraction

C.
multiplication

D.
division

Answer 1

for which operations, if you operate, do you get a result that is in the set {-1,1} ?

Answer 2

will medal and fan!

Answer 3

lets try addition:
-1 + 1 = 0 , but 0 is not in the set {-1,1}

Answer 4

@perl divison

Answer 5

?

Answer 6

@sleepyjess

Answer 7

yes division works

Answer 8

what does closed with resect to division mean?

Answer 9

and multiplication, right?

Answer 10

can you figure that one out?

Answer 11

maybe.

Answer 12

what does closed mean?

Answer 13

a set that includes all the values obtained by application of a given operation to its members. @zzr0ck3r

Answer 14

that would be a closed set

so for multiplication, is it true that if we multiply any two elements in the set, we get back another element in the set?

hint:
1*1=?
1*-1=?
-1*1=?
-1*-1*=?