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On April 08 2011 23:31 ztoa03 wrote:
As of the time of this post...the result of the first poll
288 [(1781)57%] and 2 [(1354)43%]
contradicts with the result of the third poll
1/(2*x) [(1415)68%] and (1/2)*x [(672)32%]
Right or wrong, it's common practise in a lot of places to see it as the first alternative when you are dealing with variables (x) but not if pure numbers. That's said, both problems are badly formated and any serious person would clarify with parentheses or some other mean.
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On April 08 2011 23:31 ztoa03 wrote:
As of the time of this post...the result of the first poll
288 [(1781)57%] and 2 [(1354)43%]
contradicts with the result of the third poll
1/(2*x) [(1415)68%] and (1/2)*x [(672)32%]
Not necessarily because the first poll uses ÷ and the second poll uses / for division. It depends on what meaning people assign to these two signs. If they are identical, then the polls contradict each other. If they are not, they are fine. The thing is, ASCI notation of mathematic formulas is pretty unclear unless you add a whole bunch of brackets.
LaTeX this shit and be done with it.
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My calculator makes the same interpretation of the notation as I do which is nice :p
1/2*3 = 1.5
1/2(3) = 0.166...
That's also how everyone I know i real life from students to lecturers would write it. (Yea 1/2(3) is obviously retarded but 1/2x is almost common.)
Voted 2, realise it's technically "wrong" but it's a misstake I am going to deliberately keep making since if I ever read 1/2x in real life odds are very big that the author indeed inteded to write 1/(2x)
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On April 08 2011 23:31 ztoa03 wrote:
As of the time of this post...the result of the first poll
288 [(1781)57%] and 2 [(1354)43%]
contradicts with the result of the third poll
1/(2*x) [(1415)68%] and (1/2)*x [(672)32%]
Honestly I believe that was the whole point of him starting this thread. Everyone who answers 288 should read 1/2x as (1/2)*x or (x/2), while everyone who votes as 1/2x = 1/(2x) would answer 2.
From a purely observational standpoint the question is intentionally left obscure. For those who are not vigilant in standing by mathematical rules, it is easy to see the question how you want to. Algebra is one of the hardest things to actually be consistent with without many, many years of practice, and this question is actually some proof of that.
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Could it be safe to say that we could re-write the equestion as such:
48 × ½(9+3)
I mean, division is just multiplication using the reciprocal of the divisor. It also forces the previous explanation of using the distributive property to also receive the answer of 288.
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On April 08 2011 23:37 nihlon wrote:Show nested quote +On April 08 2011 23:31 ztoa03 wrote:
As of the time of this post...the result of the first poll
288 [(1781)57%] and 2 [(1354)43%]
contradicts with the result of the third poll
1/(2*x) [(1415)68%] and (1/2)*x [(672)32%] Right or wrong, it's common practise in a lot of places to see it as the first alternative when you are dealing with variables (x) but not if pure numbers. That's said, both problems are badly formated and any serious person would clarify with parentheses or some other mean.
I thought the whole point of the convention of PEDMAS (parenthese, exponent, division/multiplication (same priority), addition/substraction (same priority).
The whole point of the convention is clarity. The fact that most people aren't aware of the convention and have developped bad habits interprating certain situations is there fault. There is no error in his formating, it's just people are use to see a situation which is wrong, but due to habit they don't reflect that there view is wrong and there wrong interpratation of a wrong format happens to work for them since of some unknown code.
There is no fault in the writing, and I know of no other convention in mathematics beside PEDMAS. If there is a graduate math student *cough* Day[9]*cough* that could inform me that in some country there is a different convention I'd be glad to hear it. But if not I recognize that the global convention is PEDMAS and people just don't know it, or follow it to a T.
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delete this edit intodouble post
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48÷2(9+3)
iirc, bracket do not disappear even after solving
so it becomes
48÷2(12)
and as you guys mentioned BODMAS, bracket still has priority so,
48÷24 = 2
this is how my thought process is, tbh i doubted my own answer seeing so many people saying 288 but I'm adamant answer is 2
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In reality the answer is that that it is gibberish. Like a badly punctuated sentence there are multiple ways of "fixing it" with your own punctuation to make it make sense.
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The problem is stupid, because no one uses the division sign the problem used - it implies that the 2(9 + 3) is in brackets, even though its not.
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Bedmas
Brackets = the 9 + 3 = 12
Then it becomes 48 / 2 (12)
The 12 in the bracket is the same thing as 2 x 12
Division before multiplication.
48/2(12)
24(12)
288
EZPZ, grade 12 highschool student
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On April 08 2011 23:47 theSkareqro wrote:
48÷2(9+3)
iirc, bracket do not disappear even after solving
so it becomes
48÷2(12)
and as you guys mentioned BODMAS, bracket still has priority so,
48÷24 = 2
this is how my thought process is, tbh i doubted my own answer seeing so many people saying 288 but I'm adamant answer is 2
inside the bracket man, not outside
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Why is 10^0 = 1? I just don't understand it. :S
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Becuase if you have 10^5 and divide it by 10^5 you would get 1 still which would be 10^0
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On April 08 2011 23:51 Arnstein wrote:
Why is 10^0 = 1? I just don't understand it. :S
Its basically per definition. There is not much to understand beside that it makes a lot of sense to define it that way 
If you want to have an explanation WHY it makes sense, just tell me to do so, i´d have to look up quite some stuff to write it in english, so I´m not that motivated to do so when theres a possibility than nobody cares anyway
Edith : post above me is quite a good argument / a good way to understand it.
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It's okay, I can ask a professor at my university
However, if anyone wants to help me, I would really appreciate it if someone could explain how to do "New definitions 2" on Khan Academy. There's no video to explain it :S I don't even understand the signs 
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On April 08 2011 22:44 lofung wrote:
this is a horribly defined question. as a math major i refuse to answer until further clarifaction.
I guess after 70 pages somebody has finally won the thread
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The best part of this thread are the people that are so convinced that the answer is 2.
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On April 08 2011 23:51 Arnstein wrote:
Why is 10^0 = 1? I just don't understand it. :S
Basically because a integer power is a multiplication and the neutral element for the multiplication is 1.
Or because 10^0 = exp(0*ln(10))=exp(0)=1, if you use real power definitions.
More troubling is 0^0's definition, but that is another debate : D
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On April 08 2011 23:45 NPF wrote:Show nested quote +On April 08 2011 23:37 nihlon wrote:On April 08 2011 23:31 ztoa03 wrote:
As of the time of this post...the result of the first poll
288 [(1781)57%] and 2 [(1354)43%]
contradicts with the result of the third poll
1/(2*x) [(1415)68%] and (1/2)*x [(672)32%] Right or wrong, it's common practise in a lot of places to see it as the first alternative when you are dealing with variables (x) but not if pure numbers. That's said, both problems are badly formated and any serious person would clarify with parentheses or some other mean. I thought the whole point of the convention of PEDMAS (parenthese, exponent, division/multiplication (same priority), addition/substraction (same priority). The whole point of the convention is clarity. The fact that most people aren't aware of the convention and have developped bad habits interprating certain situations is there fault. There is no error in his formating, it's just people are use to see a situation which is wrong, but due to habit they don't reflect that there view is wrong and there wrong interpratation of a wrong format happens to work for them since of some unknown code. There is no fault in the writing, and I know of no other convention in mathematics beside PEDMAS. If there is a graduate math student *cough* Day[9]*cough* that could inform me that in some country there is a different convention I'd be glad to hear it. But if not I recognize that the global convention is PEDMAS and people just don't know it, or follow it to a T.
Berkeley professor of mathmatics Hung-Hsi Wu disagrees with you:
"designed to trap an unsuspecting person by phrasing it in terms of a set of unreasonably convoluted rules"
This is a case of bad notation. In fact no one in their right mind would ever use the symbol "÷" for anything (I had to copy it from the OP since I have no clue how to make one)
But all that aside, it seems many people got it wrong for complete all reasons. There seems to be a trend of NAs assuming division takes priority over multiplication. I'll assume it has to with that PEDMAS thing. Where I'm from we were just taught the order of operations without any silly mnemonic and that worked out just fine. Especially since PEDMAS is kinda flawed since it's P>E>(DM)>(AS) and not P>E>D>M>A>S
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EPT
