Question

Which equations show that the set of whole numbers is closed under multiplication?



Choose all answers that are correct.



A.


–1 • –1 = 1


B.


0 • –1 = 0


C.


0 • 2 = 0


D.


2 • 1 = 2
@Directrix

Answer 1

First up, you have to know how the set of whole numbers looks

It is the set {0,1,2,3,4,5,........}

Think of it as being the set of positive integers together with the number zero.

Answer 2

a and D i think

Answer 3

Why did you choose option A?

Answer 4

Because it seemed liked it to me

Answer 5

That's not how these questions are answered.

In the option A,

it says -1 times -1 = 1 helps prove closure of the whole numbers.

Answer 6

Well, it does not.

Answer 7

Because -1 is not in the set of whole numbers so there's no need to think about it.

Closure has to do with two numbers IN the set being operated on and yielding a result that is ALSO in the set.

Answer 8

ok

Answer 9

So that means b is wrong and the answer is c andd?

Answer 10

What about this: 0 • –1 = 0 Does it support closure of the wholes under multiplication?

Answer 11

Are 0 and -1 whole numbers?

Answer 12

no

Answer 13

So, no need to consider them. Option B is OUT along with Option A.

What about this:

0 • 2 = 0

Is this the product of two whole numbers giving a whole number?

Answer 14

Are 0 and 2 whole numbers? And, is their product of 0 a whole number?

Answer 15

2 is

Answer 16

Yes, 2 is but 0 has to be a whole number also and it is.

Answer 17

Ask yourself the same questions about the numbers in this expression:

2 • 1 = 2

Answer 18

Closed or Not Closed?

Answer 19

closed

Answer 20

Correct. So,, the final answer is Options C and D show that the set of whole numbers is closed under multiplication.

Answer 21

ok

Answer 22

THanks!