• flamingos-cant@feddit.ukOP
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    2 months ago

    It’s been a hot minute since I’ve had to do any serious maths, but that does roughly line up with what I remember about BODMAS. It’s just intuitively, there’s a difference between - as an infix operator (10 - 5) and - as a prefix (-3). If you where to solve x2 where x = -3, I don’t think you’d say it’s -9.

    • there’s a difference between - as an infix operator (10 - 5) and - as a prefix (-3).

      The only difference is whether it’s in brackets or not. To square the number -3 you need to put it in brackets, otherwise you’re only squaring 3.

      x2 where x = -3, I don’t think you’d say it’s -9

      That’s because anytime you substitute for a pronumeral, whatever the pronumeral represents goes in brackets. e.g. for x=3, 2x=2(3). So if x=-3, then x²=(-3)², as opposed to if x=3, we have -x²=-(3)². Whatever the pronumeral is equal to is inside brackets when you substitute.