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1*1=1 ? how to prove 
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#1
Nov1907, 04:19 PM

HW Helper
P: 6,204

1. The problem statement, all variables and given/known data
Well as the subject states..how does one prove that 1*1=1? I think you have to use proof by contradiction but I dont know what to do after assuming that it is not true. 


#2
Nov1907, 05:22 PM

HW Helper
P: 6,204

Ok I think I got it...I was told that I should start by knowing that 0*0=0 and that 11=0
such that 0*0=0 => (1+1)*(1+1)=(1*1)11+1=0 (1*1)1=0 and so 1*1=1 


#3
Nov1907, 05:36 PM

P: 45

Well, think about what you know about (1).
Then, think about what you know about (0). More specifically, note: 0 = (1 + (1)) and 0 = ((1)+1) AND 0 = 0*0. You should be able to get the algebraic proof from there. EDIT: Dang, you got it already. Good job, but don't double post, just edit your original post. 


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