• Zagorath
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      81 year 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
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      71 year 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
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      41 year 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.