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48÷2(9+3) = ? watch

  • View Poll Results: 48/2(9+3)
    2
    117
    52.47%
    288
    106
    47.53%

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    Although I think it is 288, then I would be very interested to know the answer to this:

    Wolfram, when you put in the full question, gives 288.
    If you replace 9+3 with x, and make x equal to 12 and keep the brackets around the x, it stays at 288.
    If you take out the brackets, it becomes 2.

    Why?
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    (Original post by Get me off the £\?%!^@ computer)
    So he's wrong. So what? Are you going to devote your life to correcting people who are wrong on the internet?
    I don't know what gave you that idea. Are you going to devote your life to questioning peoples motives on the internet?
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    Right! Everyone who thinks it's 2 on that side of the room!
    Everyone who thinks it's 288 on this side of the room!
    Ready?
    CHHHHHAAAAAAARRRRRRRRGGGGGGEEEEE EEE!!!!!!
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    Wolfram is taking implicit multiplication of a variable to have higher priority than normal multiplication and division.
    It appears it takes implicit multiplication of an expression to have the same priority as normal multiplication and division.

    (Which I would grant you is not unreasonable and an argument for the 288 case. My position was to give implicit multiplication higher priority in both cases).

    Edit: I still prefer my interpretation, but it's more on human nature / convenience than rules. The simplest unambiguous representation for the 288 case is 48(9+3)/2. The simplest unambiguous representation for the 2 case is 48 / (2(9+3)), which is longer, with more brackets. So, although 48/2(9+3) is somewhat ambiguous, I think it makes more sense to interpret as the 2 case, since there's no "equally nice" way of writing the 2 case. Whereas you can rearrange the 288 case to be both nice and unambiguous. So you should, if that's what you mean.

    2nd Edit: I know someone's going to post 48 / 2 / (9+3) and say that's just as short. Yes, but it's horrible, and you should never rely on left to right ordering if you can avoid it.
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    (Original post by Jallenbah)
    I don't know what gave you that idea. Are you going to devote your life to questioning peoples motives on the internet?
    I don't know. I'll see how it goes and let you know. It seems as good a way of wasting time as many others.
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    48/2(9+3)
    brackets 48/2(12)
    division 24(12)
    multiplication 288
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    BODMAS

    BRACKETS 48÷2(12)
    48÷24
    Therefore the answer is 2.
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    (Original post by joshgoldman)
    Have the people that are saying 288 heard of BIDMAS?
    Brackets, then indices, then division, then multiplication, then addition, then subtraction.
    48÷2(9+3) = 48÷2(12) = 48÷24 = 2
    It would be 288 if it was (48÷2)(9+3).
    Yes, I have heard of BIDMAS.

    I'm confused about why you have multiplied before the division. Multiplication and division are equal, and you should then move from left to right.
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    My graphic calculator fx-9860G says 2 and fy scientific calculator fx-991es says 288!

    LOL
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    (Original post by StephenP91)
    Can't these threads be closed?

    Don't know why anyone would think anything bar 2.
    Because due to the ambiguous notation, you use BIDMAS, then work from left to right, giving 288.
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    Technically it's 48/2x12, which (better written as 12x48/2) is 288, but often the notation of a/b(c+d) rather than a/bx(c+d) implies that the product of b and (c+d) is all under the division, so you get 2. (ie b(c+d) often implies (b(c+d)) ) Basically the question is not well-posed.
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    :fight:
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    (Original post by MathsLord)
    You guys are over complicating, the answer is two, look:
    48/2(9+3)
    In order to divide we must clear up the denominator = 48/18+6
    Then = 48/24 which simply equals 2.
    But you're assuming there's an extra set of brackets around the 2(9+3)
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    if you treat (9+3) as x to make the equation 48/2x or 48/24 you get two, if you turn it into (48/2)(9+3) then you get 288

    IMO it's 2, as the 2(9+3) is shown as one entity
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    (Original post by MathsLord)
    You guys are over complicating, the answer is two, look:
    48/2(9+3)
    In order to divide we must clear up the denominator = 48/18+6
    Then = 48/24 which simply equals 2.
    You're assuming there are brackets around the 2(9+3); technically the (9+3) goes atop the fraction by default. Equally, though, something written as the 2(9+3) is here is often assumed to go altogether as the denominator. Basically, the question is written badly, and the answer is thus unclear.
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    (Original post by Jonty99)
    Because due to the ambiguous notation, you use BIDMAS, then work from left to right, giving 288.
    Well as far as I am concerned:

    \frac{48}{2(12)}} = 2 Why you would read it any differently is beyond me.
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    those calculating anything but 2 failed GCSE maths I assume.
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    (Original post by StephenP91)
    Well as far as I am concerned:

    \frac{48}{2(12)}} = 2 Why you would read it any differently is beyond me.
    But you can't be sure if it should be read like that. You've assumed that.

    The way you've written it is probably how it was intended, but I don't think you can assume that. It's written ambiguously, so you just have to use BIDMAS from left to right.

    48/2(18)

    (24)(18)

    288

    It's just a badly written equation.
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    I am now truly worried by our education system. :facepalm:
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    As I have already said once: don't be abusive to other posters because you don't agree with their answer.

    Otherwise I'll close the thread. Thanks.
 
 
 

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