6/2(2+1)

[OAcesync]

I'm sure some of you have probably seen this question 6/2(2+1)

I was in an argument on twitter with people saying the answer was nine when it has to be 1 because in equation you always solve the bracket and the number attached to bracket meaning it can't be nine because if you turned 6 into X to naturally solve X you would do 9/2(2+1)= X but you can't get 6 meaning it's incorrect.

 

I strongly believe the answer is 1 but I want to understand why people think it's 9 or if I'm actually incorrect(which I don't think I am)

[Mo5]

6/2(2+1) -> 6/2*3 -> 3*3 -> 9

6/2(2+1) -> 6/2*3 -> 6/6 -> 1

Order of operations

[TheRandomness]

6/2(2+1)

6/2(3)

3(3)

9

 

That's BIDMAS logic

[OAcesync]

6/2(2+1) -> 6/2*3 -> 3*3 -> 9

6/2(2+1) -> 6/2*3 -> 6/6 -> 1

Order of operations

I know that but I was saying bracket and numbers attached should always be priority so it shouldn't be 9 even if division and multiplication have same priority

[Samfisher]

BODMAS doesn't solve numbers directly outside brackets first.  It's 9 cos you do 2+1 first, and the 3 is still in the bracket alone, then 6/2 cos Division comes before Multiplication so the division of 6/2 happens before the multiplication of the result of 6/2 and (3).

[MoYo]

yeah it can be both. You should put it like this:

(6/2)*(2+1)=9 

but 6/(2(2+1))=1

[Vlazzy]

6/2(2plus1)

6 / 2 x 3

6 / 6

1

[ALwin]

It depends whether the equation written is implying:

 

6/2  * (2+1)  or 6/[2 * (2+1)]

 

is the (2+1) below the line on the same level as the 2?

 

Normally 6/2(2+1) implies that it is not on the same level unless it is explicitly stated.

[TheRandomness]

I know that but I was saying bracket and numbers attached should always be priority so it shouldn't be 9 even if division and multiplication have same priority

This is kinda like the what colour is the dress thing. People in (my primary school/s) schools anyways are taught BIDMAS where stuff in the bracket is always done first, then everything else. 

6/2(2plus1)

6 / 2 x 3

6 / 6

1

Yeah this is now opinion/education based.

[Curufinwe_wins]

So first things first.... Implied multiplication is a bad habit.

 

Secondly YOU CANNOT AND SHOULD NOT work on the things attached to parentheses and brackets first, only what is inside them.

 

When on to operations of the same order, work left to right. By DEFINITION 4/3*2 is not the same as 4/(3*2) but is the same as 4/3*(2) and hence when using implied multiplication (even though it's a really bad habit) 4/3(2)

[Curufinwe_wins]

I know that but I was saying bracket and numbers attached should always be priority so it shouldn't be 9 even if division and multiplication have same priority

I'm sorry but this is WRONG. It is straight up incorrect.

 

That is not how implied multiplication works.

 

 

This is kinda like the what colour is the dress thing. People in (my primary school/s) schools anyways are taught BIDMAS where stuff in the bracket is always done first, then everything else. 

Yeah this is now opinion/education based.

There is no opinion on this. There is only one correct way to treat implied multiplication even if its very use leads to these sort of mistakes (hence why it is highly discouraged in proper form).

 

In the absence of additional information...

 

4/3(2) is always to be treated as 4/3*(2) which is 8/3.

[ALwin]

snip

 

 

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If you want the equation to result in 1 as the answer, it would be written 6/[2(2+1)].

 

6/2(2+1) is the same as 6/2 * (2+1) where the (2+1) = 3, not 1/3.

 

You can even write it out on paper:

 

6 * (2+1) = 9

2

[Josephdalepi]

pemdas motherfuckers

dont forget that m and d take place at the same time

so

6/2*3

3*3

9

theres no way that its one, im  sorry

[SparkySamZa]

wow, BIDMAS, simple. so guess what it's 9....

[Curufinwe_wins]

pemdas motherfuckers

dont forget that m and d take place at the same time

so

6/2*3

3*3

9

theres no way that its one, im  sorry

So there is a bit of historical information here, even if it was due to laziness of convention and poor text scripting... 

 

Certain physics textbooks use the convention IN THEIR WRITING that 1/2x is 1 over the quantity 2x. Now the reason for that is that prior to digital type faces it was not possible to easily write fractions with complex numerators. So instead of using lots of additional divisors or brackets they decided to consider all that followed a / as under the / until the next explicit multiplication on the same order. This WAS ONLY DONE as a way to conveniently publish complex equations.

 

Again implicit multiplication should be avoided whenever possible, but in the absence of information to the contrary, in both handwritten and LaTeX formatting (by far the most common formatting used in modern publications) implicit multiplication should always be assumed to be directly substituted by explicit multiplication in location with left to right movement of the same order functions.

[Josephdalepi]

So there is a bit of historical information here, even if it was due to laziness of convention and poor text scripting... 

 

Certain physics textbooks use the convention IN THEIR WRITING that 1/2x is 1 over the quantity 2x. Now the reason for that is that prior to digital type faces it was not possible to easily write fractions with complex numerators. So instead of using lots of additional divisors or brackets they decided to consider all that followed a / as under the / until the next explicit multiplication on the same order. This WAS ONLY DONE as a way to conveniently publish complex equations.

 

Again implicit multiplication should be avoided whenever possible, but in the absence of information to the contrary, in both handwritten and LaTeX formatting (by far the most common formatting used in modern publications) implicit multiplication should always be assumed to be directly substituted by explicit multiplication in location with left to right movement of the same order functions.

pemdas is good enough for this garbage

i know the stupid stuff behind it

[Curufinwe_wins]

pemdas is good enough for this garbage

i know the stupid stuff behind it

Indeed, although avoiding implicit multiplication is even better at preventing things from being an issue.

[Josephdalepi]

Indeed, although avoiding implicit multiplication is even better at preventing things from being an issue.

fair point

i just didnt want to get to far into this

i fear it will make me  retarded

[Decon]

It's 1 if you say everything after 6 is the denominator.  If you take the equation to be 6/[2(2+1)] then the answer is 1 be cause once you get to 6/2*3 you must realize that nothing is multiplied by three, but rather by 1/3 as it is in the denominator.  This is why I hate using / for division.

[OAcesync]

It's 1 if you say everything after 6 is the denominator.  If you take the equation to be 6/[2(2+1)] then the answer is 1 be cause once you get to 6/2*3 you must realize that nothing is multiplied by three, but rather by 1/3 as it is in the denominator.  This is why I hate using / for division.

I only used because there was nothing else, I always use fractions but even if I use fraction format I don't see how you could form 9 but oh well

[BrianS]

[Ryoutarou97]

This is why I use copious parentheses. It's ambiguous wording (numbering?) so it could be either way. I would get 9, though.

[Guest Kloaked]

Follow PEMDAS (Parenthesis, Exponents, Multiplication, Division, Addition, Subtraction) with the from left to right rule. I'm not any sort of mathematician, quite the opposite, but even I know that. 

 

 

Even Google knows.