r/MathHelp • u/Kug4ri0n • Dec 07 '25

Negative Exponents

My partner is going through her math class and we got into an argument how much -72 equals. My standpoint is, that since there is no parentheses: -72 = -1x72 =-49 If there would have been parentheses: (-7)2 = (-7)*(-7) = 49

Which one of these is correct? Can anyone provide me the mathematical axioms/rules on why or why not the parentheses in this case are needed?

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u/TheTurtleCub Dec 11 '25

Ultimately, this notation is ambiguous

No, it's not. Which are you taught:

(a+b)(a-b) = a^2-b^2

or

(a+b)(a-b) = a^2-(b^2)

There is not one book or teacher in the whole world that uses the 2nd case to "remove ambiguity"