You are mistaking the notation for the object. There is indeed two ontologically different elements 3 and (-3) in Z. The question is however purely about what

You are mistaking the notation for the object. There is indeed two ontologically different elements 3 and (-3) in Z. The question is however purely about what is the meaning of the ambiguous without precedence rules representation -3^2. Note that it gets more complicated quickly if you want to keep thinking about it in that mathematicians often consider ontologically different but equivalent operations as the same when it’s irrelevant to what they are doing or the results trivially extend to both case. See for example 3-3 and 3+(-3).