• Aermis@lemmy.world
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    1 year ago

    If you agree that parenthesis go first then the equation becomes 8/2x4. Then it’s simply left to right because multiplication does not take precedence over division. What’s the nuanced talk? That M comes before D in PEMDAS?

    • I Cast Fist
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      1 year ago

      My observation was mainly based on this other comment

      https://programming.dev/comment/5414285

      In this more sophisticated convention, which is often used in algebra, implicit multiplication is given higher priority than explicit multiplication or explicit division, in which those operations are written explicitly with symbols like x * / or ÷. Under this more sophisticated convention, the implicit multiplication in 2(2 + 2) is given higher priority than the explicit division in 8÷2(2 + 2). In other words, 2(2+2) should be evaluated first. Doing so yields 8÷2(2 + 2) = 8÷8 = 1. By the same rule, many commenters argued that the expression 8 ÷ 2(4) was not synonymous with 8÷2x4, because the parentheses demanded immediate resolution, thus giving 8÷8 = 1 again.

    • If you agree that parenthesis go first then the equation becomes 8/2x4

      No, it becomes 8/(2x4). You can’t remove brackets unless there’s only 1 term left inside. Removing them prematurely flips the 4 from being in the denominator to being in the numerator, hence the wrong answer.

      • Aermis@lemmy.world
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        8 months ago

        No it doesn’t? You treat parenthesis as it’s own variable or equation. X/Y*Z. X is 8. Y is 2. And z is 2+2, or 4. Why did you add brackets to the 2? They were never there from the first equation. You can’t just multiply Y to Z and ignore X.

        • You treat parenthesis as it’s own variable or equation

          Exactly! 2(2+2) is a Term subject to The Distributive Law

          X/Y*Z.

          But it isn’t. It’s X/YZ.

          Why did you add brackets to the 2?

          I put back the brackets that you had prematurely removed when you wrote 8/2x4. You can’t remove brackets unless there is only 1 term left inside. 2(4)=(2x4)=(8)=8. When you removed the brackets prematurely you flipped the 4 from being in the denominator to being in the numerator, hence the wrong answer.

          They were never there from the first equation

          Yes they were. The original equation is 8/2(2+2).

          • Aermis@lemmy.world
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            8 months ago

            Considering how conflicting and confident we are that we are both correct, clearly there’s an issue with order of operations and how brackets work. Otherwise this wouldn’t be such a debating issue. We were taught that 2(2) is the same as 2x2.

            • Otherwise this wouldn’t be such a debating issue

              It’s not in debate in any Maths textbooks, which is something none of the people claiming ambiguity ever reference.

              We were taught that 2(2) is the same as 2x2

              It’s the same as (2x2), which is 1 term, not 2x2, which is 2 terms, which is why you can’t prematurely remove the brackets. See worked example in this textbook…