Help Please! Medal and fan!

Is the set of multiples of 4 closed under addition? Explain why or provide a counterexample if not.

A.
Yes, because the sum of any two multiples of 4 is also a multiple of 4.

B.
Yes, because the sum of any two multiples of 4 is also a multiple of 8.

C.
No, and a counterexample is –4 + (–8) = –12.

D.
No, and a counterexample is 26 + 16 = 42.

Question

Help Please! Medal and fan!

Is the set of multiples of 4 closed under addition? Explain why or provide a counterexample if not.
 
 A.
Yes, because the sum of any two multiples of 4 is also a multiple of 4.
 
 B.
Yes, because the sum of any two multiples of 4 is also a multiple of 8.
 
 C.
No, and a counterexample is –4 + (–8) = –12.
 
 D.
No, and a counterexample is 26 + 16 = 42.

anonymous · Answer

well first you need to figure out the multiples of 4

anonymous · Answer

@MCMURPH55 okay! i do know them.

anonymous · Answer

@MCMURPH55 4,8,12,16,20,24,28,32...ETC...

anonymous · Answer

so can you add 4 +4 and it = 8

anonymous · Answer

@MCMURPH55 I got it, thanks! I just didn't understand closed under addition meant.

anonymous · Answer

well its not really anything to worry about its just asking  if you can add multiples of 4 and still be a multiple