• Coreidan@lemmy.world
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    11 months ago

    Left to right. If you’re following ALL of the rules of PEMDAS then the answer is 16

      • Zagorath@aussie.zone
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        11 months ago

        The answer is 1, but the logic you’ve used to get there is a little off. Different groups actually follow different logic, but they usually arrive at the same end-point.

        The American Mathematical Society goes:

        • Brackets
        • Indices
        • Multiplication indicated by juxtaposition
        • Regular multiplication and division
        • Addition and subtraction

        While the American Physical Society does

        • Brackets
        • Indices
        • Multiplication
        • Division
        • Addition and subtraction

        In both cases, addition and subtraction are equal in priority (this solves the problem brought up by a different comment where following primary school BIDMAS would mean 8-4+2=2). In one case (and this is the way I prefer to do it) they solve the problem by declaring that implicit multiplication is done before division, but explicit multiplication with the × sign follows the same rules you would have learnt in primary school. The other says all multiplication is done before division, including explicit multiplication.

      • NikkiNikkiNikki@kbin.social
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        11 months ago

        Multiplication and division have the same priority, whichever one comes first LTR is the one that gets resolved first, so it’s (8 / 2) * 4

      • Justin@lemmy.jlh.name
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        11 months ago

        By that logic: 8-2+4=2

        Of course, it could be kind of ambiguous, but typical convention gives multiplication/division the same priority, as it does addition/subtraction.

        And in general, you need to go left to right when dealing with division and subtraction, if other operations have the same priority.