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You are not logged in. #1 20130803 04:44:22
Proof question.I have a question concerning a proof that two negatives makes a positive :
One thing which I do not follow is, why the need to prove that 15 is really 15 ? We know that, (5)+(5)+(5)=15 Last edited by AlAllo (20130803 04:45:04) #2 20131106 01:06:42
Re: Proof question.
is by definition the additive inverse of , i.e. the unique integer such that .
To prove that an integer is equal to , add it to 15 and show that it equals zero. Thus, to prove that , you need to show that . That is all the proof is doing. No other properties of are assumed. Last edited by Nehushtan (20131106 19:11:25) 134 books currently added on Goodreads 