48÷2 (9+3) argument

[Archer]

Look I agree it's 288 if you follow the rules

So why are you being dumb and insisting its 2 then by not following the rules? :wtf:
I didnt know we can randomly decide when to follow the rules in math.

let x= 1+6, y = 2-1
1+6/2-1/2-1
= 2.5?
or is it
(1+6)/(2-1)/(2-1)
=7?

M+y point was parenthesis is very important. yes there are trivial equations where it is not needed. but in many case ambiguity can arise when they are not used.

Well done failing at substituting. That was actually really bad dude. Really really really bad. You've not proven anything about the importance of brackets, only how bad at substituting you are. I'm actually embarrassed for you, thats how bad the above is...

So in summary
You claim 48/2(9+3) -> 48/(2(9+3) .... how else would you get to the answer of 2
You also claim that 48/2(9+3) -> 48/2*(9+3) -> 288 ... according to the first quote in this post

So now you are arguing that 48/(2(9+3) = 48/2*(9+3)
Can you now understand why you are wrong? You admit yourself it can go both ways, but it can only do that because you apply some special case logic to it. So why not (cue shock and horror) dont you just follow the rules properly all the time, and not get mixed up...

 

[nakedpeanut]

So why are you being dumb and insisting its 2 then by not following the rules? :wtf:
I didnt know we can randomly decide when to follow the rules in math.



Well done failing at substituting. That was actually really bad dude. Really really really bad. You've not proven anything about the importance of brackets, only how bad at substituting you are. I'm actually embarrassed for you, thats how bad the above is...

So in summary
You claim 48/2(9+3) -> 48/(2(9+3) .... how else would you get to the answer of 2
You also claim that 48/2(9+3) -> 48/2*(9+3) -> 288 ... according to the first quote in this post

So now you are arguing that 48/(2(9+3) = 48/2*(9+3)
Can you now understand why you are wrong? You admit yourself it can go both ways, but it can only do that because you apply some special case logic to it. So why not (cue shock and horror) dont you just follow the rules properly all the time, and not get mixed up...

lol MEGA FACEPALM!

trololololololololololol

I really have no other way of saying parenthesis is ****ing important!?
Lets recap this:
1) In school many were taught to interpret 48/2(9+3) as 48/(2(9+3)) and 48/2*(9+3) as (48/2)*(9+3) due to teachers unable to print it out correctly in tests. Hence I and many others interpret it as 2...
2) I agree that written as it is without the bias of (1) it is 288.

You following?

3) My substitution is perfect but writing it all out in one line is why you require parenthesis! Case in point this troll question.
4) No Mathematician would ever write it out like my example nor the question of this OP.
5) If you do you need a slap or parenthesis.

6) .. profit?


I refuse to waste any more time in this idiotic thread.

 

[JungleBoy]

Three days later and this is still raging on...F#cking unbelievable.

We've been trolled -

 

[Bar0n]

Firstly, this is a trolling attempt, it originated from 4chan and it's been going on for probably about a year now.

Secondly, the question is completely ambiguous, and badly written and it could be interpreted as either 2 or 288.

The reason Google says it's 288 is because it works from left to right. As humans we tend to scurry towards completing the values in brackets, but in reality 2(9+3) = 2 * (9+3) and doing it from left to right will result in 288 again.

You were taught to do brackets first, but the 2 does not form part of the brackets.

Again, it is simply ambiguous, and a troll, and no-one is really right here. It all depends on your interpretation. (I am a postgraduate student in maths so hopefully I know what I'm talking about here.)

 

[JungleBoy]

Look at Homer's troll face

 

[noxibox]

M+y point was parenthesis is very important. yes there are trivial equations where it is not needed. but in many case ambiguity can arise when they are not used.

Brackets are a means to override operator precedence. Your two examples are different equations, both of which are completely unambiguous, giving only one correct result.

Secondly, the question is completely ambiguous, and badly written and it could be interpreted as either 2 or 288.

It's only ambiguous to someone who cannot read a basic single-line equation. It's exactly the sort of equation to throw at children to see if they know their precedence rules. It was common practice when I was at school to use questions the teacher knew would fool those who didn't know what they were doing. Apparently they'd fool a lot of adults too.

 

[Bar0n]

It's only ambiguous to someone who cannot read a basic single-line equation. It's exactly the sort of equation to throw at children to see if they know their precedence rules. It was common practice when I was at school to use questions the teacher knew would fool those who didn't know what they were doing. Apparently they'd fool a lot of adults too.

No. The question should be put in such a way that multiplication and division could be done in any order. (And no, division does NOT precede multiplication as is commonly believed, division is only the multiplication of the inverse, so it is the same operator, and has the same precedence.)

This question is ambiguous and has no clear answer.

 

[zippy]

No. The question should be put in such a way that multiplication and division could be done in any order. (And no, division does NOT precede multiplication as is commonly believed, division is only the multiplication of the inverse, so it is the same operator, and has the same precedence.)

This question is ambiguous and has no clear answer.

Maths is NEVER ambigious. It only seems ambigious if you dont know the rules of precedence.

The question has a clear answer

x= 48 / 2 x (9+3)
x= 48 /2 x (12)

The mistake is try to multiply (12) by 2. This is because you can't visualise that the "2" is below the line and "48" and the resolved (9+3) are "above" the line

x= 48 12
----- x ----
2 1

get the denominators to 1:

x = 24 12
---- x ----
1 1

x = 24 x 12
x =288

The spacings below are thrown out, when I save the post. But try to see that there are 2 expressions here:
49
-
2


and
(9+3)
---
1



Its not ambigious. Not at all.

 

[ScottulusMaximus]

48/2 (9+3) is 24 12, end of story. There is no point arguing about it because it is not in mathematical nomenclature so is a pointless question, if it was 48/2(9+3) then you can argue...

EDIT:- actually you can't argue if the question was 48/2(9+3) the answer would be 2 and if it was 48/2x(9+3) it would be 288 but as it stands the answer is 24 12...

 

[Mike Hoxbig]

Maths is NEVER ambigious. It only seems ambigious if you dont know the rules of precedence.

As mentioned earlier, the order of operations is an agreed upon rule to help eliminate ambiguity. It is not mathematical fact. That there are exceptions to the rule, proves this.

Division is the multiplicative inverse, so one should be able to divide or multiply in any order, as it is with addition and subtraction. If you obtain two different results then there is clearly a problem with the notation used in the equation, and no amount of shouting "left to right" will fix that.

 

[zippy]

As mentioned earlier, the order of operations is an agreed upon rule to help eliminate ambiguity. It is not mathematical fact. That there are exceptions to the rule, proves this.

Division is the multiplicative inverse, so one should be able to divide or multiply in any order, as it is with addition and subtraction. If you obtain two different results then there is clearly a problem with the notation used in the equation, and no amount of shouting "left to right" will fix that.

Obtaining 2 different results means you made a mistake and dont know your math.

 

[Mike Hoxbig]

Obtaining 2 different results means you made a mistake and dont know your math.

I'm pretty sure I know my maths. Obtaining two results by choosing whether to divide or multiply first, means that there is a problem with the expression.

 

[MrGray]

Secondly, the question is completely ambiguous, and badly written and it could be interpreted as either 2 or 288.

*FACEPALM* Are you trying to contribute to the trolling? The question is NOT completely ambiguous, despite it being poorly written.

The reason Google says it's 288 is because it works from left to right.

The reason Google "works from left to right" is not because they though it would be nice way to do things, it is because it is the fundamental rule of mathematics. Again, no room for ambiguity.

You were taught to do brackets first, but the 2 does not form part of the brackets.

I've noticed that many people mistake "doing the brackets first" with doing the distribution first. Doing the brackets first means adding the (9+3) to get (12) first and NOT 2*9 + 2*3.[/QUOTE]

Again, it is simply ambiguous, and a troll, and no-one is really right here. It all depends on your interpretation.

No it doesn't.

(I am a postgraduate student in maths so hopefully I know what I'm talking about here.)

I can only hope you're trying to add fuel to the fire

If you are really a postgrad maths student then I would expect you'd have a keen appreciation for how your field would not function very well if everyone applied their own opinion of how to calculate equations.

 

[MrGray]

No. The question should be put in such a way that multiplication and division could be done in any order.

The question is not put in such a way. In fact, there is actually no way to express an equation in such a fashion that the order of precedence would be in doubt, because the order of precedence exists independently of any question.

 

[MrGray]

48/2 (9+3) is 24 12, end of story. There is no point arguing about it because it is not in mathematical nomenclature so is a pointless question, if it was 48/2(9+3) then you can argue...

EDIT:- actually you can't argue if the question was 48/2(9+3) the answer would be 2 and if it was 48/2x(9+3) it would be 288 but as it stands the answer is 24 12...

In mathematical nomenclature this expression:

2x

always means:

2 * x

So why would 48/2(9+3) ever mean anything other than 48/2 * (9+3) ?? Answer: it wouldn't. Ever. Therefore, there is no ambiguity regardless of nomenclature.

 

[Mike Hoxbig]

it is because it is the fundamental rule of mathematics.

No, it's not. This is the fundamental theorem of arithmetic. Arithmetic != mathematics, I wish people would learn the difference.

 

[Bar0n]

*FACEPALM* Are you trying to contribute to the trolling? The question is NOT completely ambiguous, despite it being poorly written.

I'm afraid it is.

The reason Google "works from left to right" is not because they though it would be nice way to do things, it is because it is the fundamental rule of mathematics. Again, no room for ambiguity.

AFAIK left to right is convention, but not necessarily a rule. A proper problem is free of ambiguity like this, by adding more brackets. What If I'm asian or arabic and read from right to left?

Also see: http://en.wikipedia.org/wiki/Order_of_operations#Exceptions_to_the_standard

The precedence of an implied multiplication e.g. 2x being 2 × x also varies by source. For example, Wolfram Alpha considers that implied multiplication precedes division, e.g. 2x÷2x gives 1 instead of x²,[5] except where parentheses are adjacent, e.g. 48÷2(9+3) gives 288 instead of 2.[6]

I've noticed that many people mistake "doing the brackets first" with doing the distribution first. Doing the brackets first means adding the (9+3) to get (12) first and NOT 2*9 + 2*3.

What's your point? It's the same answer.

No it doesn't.

I assure you it does.

I can only hope you're trying to add fuel to the fire

If you are really a postgrad maths student then I would expect you'd have a keen appreciation for how your field would not function very well if everyone applied their own opinion of how to calculate equations.

You can try to insult me or my intelligence all you want, but the fact is that this problem is ambiguous, else it would not destabilise into a fiasco on ever forum it's posted. Nobody is applying their own opinion because nobody writes math this poorly. It's done on purpose to cause a heated debate.

.

 

[Bar0n]

The question is not put in such a way. In fact, there is actually no way to express an equation in such a fashion that the order of precedence would be in doubt, because the order of precedence exists independently of any question.

Really? What if I change it to the following:

1) (48 / 2)(9+3)

or

2) 48 / (2(9+3))

That is how it should be written to be unambiguous.

 

[Bar0n]

No, it's not. This is the fundamental theorem of arithmetic. Arithmetic != mathematics, I wish people would learn the difference.

Haha, nice. I like when people throw terms like "fundamental theorem or rule" around without knowing that it actually exists.

 

[ScottulusMaximus]

In mathematical nomenclature this expression:

2x

always means:

2 * x

So why would 48/2(9+3) ever mean anything other than 48/2 * (9+3) ?? Answer: it wouldn't. Ever. Therefore, there is no ambiguity regardless of nomenclature.

get a pen and paper and write out 48/2(9+3) with the (9+3) with the 2 as the divisor then write out 48/2 x (9+3)/1 and do the maths, you will get 2 for the first one and 288 for the second one, either one of them can be derived from the original question... A space has no meaning in mathematics nomenclature other than to separate 2 equations therefore 48/2 (9+3) is 24 (12). All these rules you are shouting about mean nothing when the question is fundamentally flawed...

Or just listen to bar0n, he explains it much better...