Facebook debacle.
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29 Apr 2011, 22:30
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6÷2 (1+2) = ?
Having plenty of discussions about the right answer on this one, feel free to solve this "hard" formula.
PS : Mapple says it's 9, so do alot of online specialized calculators.
Having plenty of discussions about the right answer on this one, feel free to solve this "hard" formula.
PS : Mapple says it's 9, so do alot of online specialized calculators.
1+2 is 3
11
easy
Brackets then Order then Division
6÷2(1+2)
6÷2(3)
6÷6
1
never heard of pedmas, only did math till intermediate level
fml
how the fuck do you get 9 out of it
6/2(1+2) =
6/2*3 =
6/6 =
1
so 1 is the answer
4x4 = 16
if the sum was 6(1+2)/2 then it would be 9
or if it was (6/2)(1+2) then it would also be 9
but the sum is 6/2(1+2) = 6/2*(1+2) = 6/(2*(1+2))
6/2x3 = 9
6/2= 3 x 3 = 9
WTF
e: 3(3) = 9 lmfao
1. Brackets first = 6/2 * (3)
2. Division and Multiplication (left-to-right) = 3 * 3
3 * 3 = 9
2*3 is the denominator (i.e. the bit on the bottom)
so its 6/6
otherwise it would be 6*3/2 which would be 9
Especially that the author posted "÷", not "/".
(2*1 + 2*2)
the 2 distributes over the brackets
6/2(1+2) is just 6/(2*1 + 2*2)
the use of the other notation is neither here nor there
The lack of * doesn't change anything. 2(1+2) is the same as 2*(1+2). So that you have 6/2*(1+2).
The first thing to do is to solve operation in the bracket. Then you have 6/2*3. And then you go from left to right. You cannot distribute just 2 over the bracket, because there is a rule of "left to right".
If you want, you can distribute 6/2 over the bracket, not just 2. Apart from the fact that there is no variable so it's pointless as the score is the same.
e: Never finished 1st year of highschool, got kicked out 3times :x
6 / 2 (1+2) = 1/6 * 2(1+2)
Now you have a calculation only consisting from multiplications.
1/6 * 2(3)
1/6 * 6
= 1
then you times 6/2 with 3 and you get 9.
divide both sides by (1+2), what you get left is: 6 / 2 = 1 / 6 * 2 => 3 = 1/3? nice math
6 ----------------- 6
------------- = ---------- = 1
2 * (1+2) -------- 6
=D
Edit: Might be clearer if:
(6) / (2*(1+2))
so first do (1+2)=(3) then 6:2=3 then 3(3)=9
I'd go for one simple because nobody would write (6/2) . (1+2) when leaving the 1st bracket out cos its confusing, i'd write (1+2).6 / 2 which is clearly 9, therefore writing it differently would be 1 imo
But the rule without brackets is:
1. power
2. div/multiplication
3. + & -
So geegee, its both!
There is this simple rule of reading from left to right you know
edit: (1+2) 2 ÷ 6 . NOW WHAT HUH?
There is this simple rule of reading operations of equal priority from left to right you know.
fucking idiot
He now clarified his comment by explaining its only with equations of the same priority, which makes it a completely different situation ;)
In fact you are both right, it just depends on how you read the question (the main one in the journal!). :)
:D
6x15-2 = ?
= 88
conspiracy? didnt think so.
mabi
no mabi not
6
_(2+1)
2
do parenthesis
6
_ 3
2
by order its either
6x3=18/2=9
or
6/2=3x3=9
this should be like uber insta triviality for people >4th grade
EDIT: I've never seen in any math problem I had to solve 2(1+2) to be interpreted the way so many people according to the vote do interpret.. it must be 9
One could also that 1÷4x (aka 1÷4(x)) would be 1÷4*x, which would be 0,25x, it's clear that it's 1÷4x
e: and 2(1+2) is just another way to write 6, same way you could write 4 with 2(2) or (x+x) as 2x
1÷4x is precisely 0,25x.
Sure, if someone writes 1÷4x, he probably wants to say 1/(4x) which is a different thing (option 2 is he wants to confuse the reader), but the rules of mathematics don't really give a fuck about what you want to mean.
Wolfram Alpha disagrees with me, but that's because its AI interprets the input in a non-literal way (it tries to understand what the person wants to ask...).
Google Calculator agrees.
If you were to write 1÷4x on paper, it would probably look more like 1 ÷ 4x, what makes it clear that 4x is the divider, and the 1 is the dividee(?).
Same is whether it's 6÷2(2+1), when it's 9, but for me it would make no sense to write it like that. 6 ÷ 2(2+1) would be much more logical, because I don't think why anyone would write a multiplication of a division and a sum all without any "spaces".
sorry for the random writing style
there is a space between 2 and (
off to bed
bye
going off to sleep now, write an answer if you may
Obviously they didn't point out it's ((5)(2)) because it's a standalone expression, so surrounding brackets are not needed, but this paragraph does imply that 2(expression) is a separate expression.. I think?
So untill googling it when kevin asked me on irc, I didnt even know that rule wasnt valid anymore since not a single math teacher told me otherwise in my life :D
Since I guess like 2003 or so that rule we used isnt valid anymore because as u stated it is incorrect. The problem is that everyone in NL uses that rule and there never has been a "big" message that it is incorrect so most people dont even know it is incorrect and just use the way it got taught to them
1+2 = 3
3*3 = 9
6/2 = 3
6 * 1/2 = 3
Back to the actual calculation:
6÷2 (1+2) = ?
So, it's 6 * 1/2*(1+2)
= 3*3 = 9
or
= 6 * ½ * 3
= 6 * 1½
= 9
So my previous conclusion was apparently incorrect, I think it's 9 now :D
6/2*3
=
3*3=9
because
5-7+3=1 and not -5
_ * (2+1)
2
<=>
3 * 3 = 9
e: but what when you do it distributive way? like this a × (b + c) = ab + ac.
6÷2 (1+2) = ?
6/(2*1+2*2)= ?
= 1
or is it like this?
6÷2 (1+2) = ?
6/2+4 = ?
3+4 = 7
PLZ RESCUE ME FROM THIS SITUATION
hahaha :D how about we swap the bracket's contents order?
6÷2(2+1)
would you say it's 6÷4+2 ? :). (btw why are you changing symbol "÷" to "/"? :]).
what you did is: you started x(a+b)=xa+xb, but in the middle of the process, you decided to use xa in some external operation. that's wrong, because to remain logical, this should be written this way
6÷2(1+2)
6÷(2+4)
That's also why you are told to do brackets first. First means BEFORE ANYTHING ELSE.
Also see my note on "÷" and "/" signs.
so is it 6÷6 = 1 ?
6/2*(1+2) <- because you first exert division, because it's on the left, and then mulitplication, because it's on the right.
6/2*1 + 6/2*2
3*1 + 3*2
3+6
9
or you can sum up the bracket first - no difference in score. 6/2*3 = 3*3 = 9.
edit: You could only distribute 2 over the bracket if the statement was 6/(2(1+2))
6÷2(1+2) is not the same as 6/2(1+2).
6÷2(1+2)
6÷2*(1+2)
3*(1+2)
3+6 (if you x(a+b)=xa+xb) or simpler 3*3 (as we don't have variables).
9
6/2(1+2) means 2(1+2) is denominator, while 6 is nominator.
6/2*3 or 6/2+4
6/6
1
Too bad google's calculator can't differentiate "÷" from "/". Too bad it's a sign on all keyboards. Calculators would need you to use fractions function (those who have it :s). Simple pressing division sign will make it "÷", not "/".
Or are these signs the other way around?
what i wrote has a sense when we talk about inline text. we only have some stupid ascii combinations for expressing limited fractions, like 1/2, 1/3, etc., so that differentation would be helpful.
does the lack of * between 2 and the bracket make a difference? like... do we need to do x(a+b)=xa+xb before dividing left of "/" by right of "/"?
6/2(1+2)
6/2+4
3+4
7
So I'm pretty much more confused than I was before.
what you did is: you started x(a+b)=xa+xb, but in the middle of the process, you decided to use xa in some external operation. that's wrong, because you have to finish the operation first. to remain logical, this should be written this way:
6÷2(1+2)
6÷(2+4)
Why I think this is logical? Because we could very well swap the order of the bracket's content, like:
6÷(2+1)
6÷(4+2) <- the result has to be in brackets, because it can be done xa+xb or xb+xa :).
That's, again, ambigous :).
edit: if you'd like to do do the division, you would have to do it before or after fully completed transition from x(a+b) to (xa+xb).
edit2: again, this is only the problem of limited capabilities of maths done in inline text you can type on the basic html page :).
Might be read as 6 ÷ 2(1+2), which is 1.
I don't know if there are any rules regarding the correct formulation in this type of texts.
it's 9 and you're def right.
So as far as improvising go, they could matter.
putting space there, like: "6 / 2(1+2)" cannot change the fact that you have to divide first and then multiply (left to right) :-).
in programming, spaces don't matter. even looking at html, <a><b></b></a> is the same as if you put thousands of spaces and newlines between any of the signs.
Anyways, pointless discussion :DD