B and E are the corect answers. For a pair of numbers to be additive inverses, that means that the sum of the two numbers must be 0. And only a pair of opposite nunbers, such as 2 and -2, can have a sum of 0.
I was never sure of what the "additive inverse" is. So, just now, just for you, I went and looked it up. The additive inverse of any number ' A ' is the number that you need to ADD to A to get zero. That's all ! So now, let's check out the choices: a), 6, -(-6) That second number, -(-6), is the same as +6 . So the two numbers are the same. Do you get zero when you add them up ? No. b). -7, 7 What do you get when you add -7 and 7 ? You get zero. So these ARE additive inverses. c). -7, -7 What do you get when you add -7 to -7 ? You get -14 . That's not zero, so these are NOT additive inverses. d). 7, 7 What do you get when you add 7 to 7 ? You get 14. That's NOT zero, so these are NOT additive inverses. e). 6, -6 What do you get when you add 6 to -6 ? You get zero. So these ARE additive inverses. What do we end up with from the list of choices: a)., c)., and d). are NOT additive inverses. b). and e). ARE additive inverses.