Question

find theadditive inverse of 5 on the 12- hour clock

Answer 1

on the 12 hour clock you only have 1,2,3,4,5,6,7,8,9,11 and 12 (or zero)

Answer 2

5 + ? = 12

Answer 3

that number will be the additive inverse of 5

in general to solve
a + x = 0 , x is the additive inverse of a

Answer 4

or, just mathematically, -5 would be the answer, not that the time can go backwards, so it's not.

Answer 5

I think both of you sort of put the pieces out there well, but to summarize, the additive inverse is clearly -5 normally.\[5-5=12\] but on a clock you can always add 12 to any number and get the same number back because it's cyclic, so we take -5 and add 12 to it \[-5+12 = 7\] And that's the more common way of representing.