Question

Which sets of numbers are closed under addition?

Choose all answers that are correct.

A.
whole numbers

B.
natural numbers

C.
negative integers

D.
integers

Answer 1

closure under an operation means that if you start with two elements in a set and then operate on them, the result will also be in the set

Answer 2

any two elements

Answer 3

one sec, draw button died on me

Answer 4

well 1 + 1 = 2 , and 2 is inside the set .
1+ 2 = 3 and 3 is inside the set

.... looks like it is closed

Answer 5

0 + 1 = 1 ,
0 + 0 = 0 , etc

Answer 6

how about a set that is not closed under an operation.
lets look at natural numbers under subtraction . is that closed?

Answer 7

, well if we pick two numbers from the set of natural numbers, how about 1 and 2.
1 - 2 = -1
but -1 is not a natural number. so the natural numbers are not closed under subtraction

Answer 8

so in your problem, A through D are closed under addition.

Answer 9

anybody home?

Answer 10

Oh hey whats up