# In my last doubt, I asked to give a formal proof, for (-)(+)=(-). I was asked by my maths teacher in school, that how when 2 unlike signs are multiplied, why the result is a negative value. Neha ma'am answered this last time, but it was not at all satisfactory.. I wanted one of the formal proofs like Brijendra Pal sir gave me for (-)(-)=(+)..Experts may prefer to that one, to make the answer satisfactory for (-)(+)=(-)...

Dear Student,

Hence proved

Regards,

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I hope to get a very satisfactory answer this time,like Brijendra sir gave me for (-)(-)=(+) .. Even if experts take more time to answer this, then too I want a very specific answer. But please don't the answer, like, when 2 unlike signs are multiplied ,we get a negative value... Hope you are very aware of my doubt , very accurately. .
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I want a very proper explained proof for this... Even it takes more time, please answer specifically, according to the proper agenda mentioned in the question...
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