48÷2(9+3) = ????

48÷2(9+3)

  • 288

    Votes: 127 43.6%

  • 2

    Votes: 152 52.2%

  • idunnololdog.jpg

    Votes: 12 4.1%
  • Total voters
    291
faceblogger said:
After seeing the poll results and replies I see a highly profitable potential business:
Write a crappy eBook copy pasting BODMAS rule and a few other basics, name it "Mathematics for Affiliate Marketeers" and sell it on WaFo, PROFIT :)
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Speaking of WaFo, I feel like we should consult Wagenheim for the official answer of this math problem. :thumbsup:
 


agj32mrgibbits said:
headasplode.jpg
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This discrepancy has actually been explained by Texas Instruments themselves here:
Does implied multiplication and explicit multiplication have the same precedence on TI graphing calculators?

Implied multiplication has a higher priority than explicit multiplication to allow users to enter expressions, in the same manner as they would be written. For example, the TI-80, TI-81, TI-82, and TI-85 evaluate 1/2X as 1/(2*X), while other products may evaluate the same expression as 1/2*X from left to right. Without this feature, it would be necessary to group 2X in parentheses, something that is typically not done when writing the expression on paper.

This order of precedence was changed for the TI-83 family, TI-84 Plus family, TI-89 family, TI-92 Plus, Voyage™ 200 and the TI-Nspire™ Handheld in TI-84 Plus Mode. Implied and explicit multiplication is given the same priority.
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nickster said:
This is where the confusion arises.

You are writing the equation in the problem incorrectly. It is not 48/2*(9+3) it is 48/2(9+3)

The fact that the 2 is right next to the brackets means that if the juxtaposition rule applies (or exists) then the 2 would need to be multiplied by the (9+3) BEFORE the division happens. This is the problem that everyone is having in understanding that the answer is not as simple as it first may seem.

I actually believe that the juxtaposition rule must exist as if you look at the following it would make no sense if it did not

10x/5x

According to the juxtaposition rule the answer would be 2

but if you ignore it then the equation should read

10*x/5*x

and if you work that out left to right then
it equates to 2x^2 which isn't right.
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I just double checked with my math professor (very respected in math field) and he confirmed this (what nickster says about general consensus).
If you write this in some code or program you add those second brackets but if you write it on paper (or anywhere for human to read, not for program) they are most likely implied.

Plus Amagz made a good find here from texas instruments:

Does implied multiplication and explicit multiplication have the same precedence on TI graphing calculators?

Implied multiplication has a higher priority than explicit multiplication to allow users to enter expressions, in the same manner as they would be written. For example, the TI-80, TI-81, TI-82, and TI-85 evaluate 1/2X as 1/(2*X), while other products may evaluate the same expression as 1/2*X from left to right. Without this feature, it would be necessary to group 2X in parentheses, something that is typically not done when writing the expression on paper.

This order of precedence was changed for the TI-83 family, TI-84 Plus family, TI-89 family, TI-92 Plus, Voyage™ 200 and the TI-Nspire™ Handheld in TI-84 Plus Mode. Implied and explicit multiplication is given the same priority.
 
dooogen said:
So who in this topic has actually taken a math class in their life?
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lol I've had 3 years of calculus, differential equations, linear algebra, and two years of math methods for theoretical physics, as well as all the physics classes of course.


csnreyes said:
Where are the brackets????

() is parentheses
[] that is brackets
a number or variable by () (e.g. x(a+1) is the same as x * (a+1)
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you do realize brackets and parenthesis when in the context of a function or equation behave the exact same, right? they're just ways of making it easier to read. They make a difference when you're talking about things like limits or bounds (i.e. parenthesis mean non-inclusive bounds, brackets mean inclusive bounds), but in this thread they behave the same.
 
I did advanced maths A-Level and studied Physics in University (although I did drop out :) )

It amazes me that mainly people with an obvious very basic level maths are chiming in and insulting everyone else for having a differing opinion to theirs on a subject that polarizes maths teachers and professors.

Papajohn I would be very interested in your take on the priority of juxtaposition in relation to my previous posts.
 
Unarmed Gunman said:
Fixed.
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Well my point is, even when we think there is a clear rule people will continue to argue it. A good enough lawyer can convince a court (rulemakers) that the previous rule was incorrect.

If there was enough money at stake the answer could be 2 or 288.
 
CygnusX said:
Yes, that's me. My name is Monika Vesela and you can sign up to my paysite here if you want to see more ;)

:offtopic:
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wow that was a surprise. I'm almost sure you are the site owner and not monika. pm me if you can prove me wrong :D
 
CygnusX said:
Yes, that's me. My name is Monika Vesela and you can sign up to my paysite here if you want to see more ;)

:offtopic:
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wow that was a surprise. I'm almost sure you are the site owner and not monika. pm me if you can prove me wrong :D
 
nickster said:
I did advanced maths A-Level and studied Physics in University (although I did drop out :) )

It amazes me that mainly people with an obvious very basic level maths are chiming in and insulting everyone else for having a differing opinion to theirs on a subject that polarizes maths teachers and professors.

Papajohn I would be very interested in your take on the priority of juxtaposition in relation to my previous posts.
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How does knowing diff eq, euclidean geometry, or anything else help with this? I knew this answer in third grade. Some times you can over think something.
 
I think this sums it up best: 48 ÷ 2(9 + 3) can be also written as 48 x ½(9 + 3) which evaluates to 288 whether you multiply the ½ first by the parentheses or by the 48.

Can somebody who is in love with the correct answer being 2 explain that?
 
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