I had asked how (-)(+) = (-)? I want a formal proof for this. 

This question was asked by my maths teacher in school... But, When I showed this, he asked that how corollary 1 is proving, (-)(+) = (-). He means to say how when 2 different signs are multiplied, how to say that the value is (-)., . Please experts make me  understand very specifically, how, (-)(+) = (-), with a formal proof...  


Dear student
Please refer to the easy and clear explanation below in a different method which will help you in understanding the concept in a better way.

There is no as such special proof for -+=-These are just simply the signs rule which states :1)  a negative  and a positive makes a negative .Example -3×2=-62) two negatives makes a positive.Example -3×-2=63) a positive and a negative makes a negative.Example 3×-2=-64) two positives makes a positive .Example 3×2=6So we can conclude that "Two like signs makes a positive sign, two unlike signs makes a negativesign".


  • -2
Well it dont have any formula😊
  • -1
As my Maths teacher asked this in school, then I hope that there is surely a very accurate and specified formal proof, and I know that the expert(like Brijendra Pal sir in Maths)  on MeritNation will surely help me out in this..

Thanking You!
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