The sum of a number and its additive inverse is equal to 0
example :...the additive inverse is the opposite of a number....the number stays the same, u just change the sign
2.....its additive inverse is -2.....because 2 + (-2) = 0
-5...its additive inverse is 5......because -5 + 5 = 0
2/3...its additive inverse is -2/3....2/3 + (-2/3) = 0