what is the additive inverse of 9/11 Share with your friends Share 0 Mocachino Abdurrahman De Lotte answered this 11/9 1 View Full Answer Pritisha.. answered this The additive inverse, or opposite, of a number a is the number that, when added to a, yields zero. So, the additive inverse of 9/11 is -9/11 3 Charvi answered this -9/11 1 Anjana answered this -9/11 0 Mohammad Ibrahim answered this -9/11 0 Siyaf Yoosuf answered this -9/11 0 Zahida answered this -9/11 0