Poll: What is the answer to 48/2(9+3)?

RonHiler

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Yes, I am wrong. Computers are wrong. Calculators are wrong. Couldn't be you.

And yes, I passed Algebra I, thanks. I also passed three quarters of calculus, and am a professional computer programmer for over 20 years now. I've done math that would make your head spin. Still want to insult my math skills?
 

Pyro Paul

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the answer is 2.

2(9+3) is the simplified form of 2*9 + 2*3
NOT
2 * (9+3)

as written the equation should be seen as
48 / (2*9 + 2*3)

which when calculated out equials 2.
 

drdamo

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Ok lets simplify:

48 = A
2 = B
9+3 = C

So now we have A/B*(C)
As you can see I haven't changed anything, I simply renamed the numbers.

In short this will become:

48 / 2 * 12 = 288

And btw:

A/B*(C) = (A/B)*(C)

Because both have the same order of operations: Devide first & Multiply second and since both have an equal priority the result goes from left to right like it has always been.

The answer will only be 2 if its written like: A/(B*(C))

Why? Because in order to change the order, when both operations have the same priority, you have to bracket the one who's priority needs to change and therefore make an exception on the left-to-right rule.

Saying (9+3) is part of the denominator is an assumption and not based on the facts that are our order of operations.
 

Skratt

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kurupt87 said:
Skratt said:
PEMDAS

(48/2)(9+3)=288
48/2(9+3)=2

Better?
BIDMAS

48/2(9+3)=288
48/[2(9+3)]=2

Better?

As many have already said, it's a poorly written problem.

The fact that "/" is used does not necessarily imply a fraction. "/" is the default sign for the operation called division and also to seperate a numerator from a denominator in computer language, this is where the problem lies.
:) I actually corrected myself when I went to lunch and discovered why I got the problem wrong. PEMDAS, which is what I was taught is an order of operations. What I forgot (or maybe never remember learning) was that M carries no more weight than D and A no more than S. So, in absence of P, the equation is solved left to right.

4*3+5=17
5+3*4=17

Correct?
 

mps4li3n

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Joseph Webb said:
mps4li3n said:
DemiGodEpsilon said:
Uhh.. not really. If you passed 5th grade math, you'd know the answer is 2.
Sarcasm, the only thing less understood then this equation.


Joseph Webb said:
You see, there's the flaw in your logic. We are not computers. It doesn't not matter how it is written for us, you should understand that (48/2)(9+3) =/= 48/2(9+3) The fact that you think that they are equal proves to me that you do not understand the distributive property. Stop arguing with your flawed logic, you will never be correct, because we will never be computers. Computers are provided with a flawed logic system in their programming, every math teacher (and decent math student) knows this.

But the thing is that in the end the symbols used and what they mean are wholly artificial and arbitrary... it really doesn't matter if 48 was writen as $* or kanji as long as it meant the same 48 pieces of whatever.


And because both variations exist in the real world the 1st question to ask is "üsing what system, the computer's or the one you know from studying math".

Problem is that no one bothered to ask that and that's why we're on page 16+
You're either a troll, or you just don't understand the situation. Do you understand how calculators work? Do you understand the flaw in their logic when calculating a problem like that? This is seriously a basic 8th grade problem that teachers use to screw up their students (and hopefully use it to teach them a lesson the won't forget about the distributive property and how their calculators are retarded). The answer is 2. If you're using the flawed logic of a calculator to solve the problem, the answer is 288. However, that answer is wrong. To type the same question into the calculator, you need to work around its flawed logic by including an additional set of parentheses. The problem you would plug into a calculator would be 48/(2(9+3)), which equals 48/2(9+3), which equals 2. The thread starter is probably a troll, because you have to have failed pre-algebra to not understand that calculators are flawed. Seriously.

Oh for crying out loud...

You might have been taught that "/" is only ever

1
---
x

with x = everything after the "/" , but not everyone was... some people only saw "/" on the computer and they assumed it simply means divided by [ 48:2x(9+4) is how we'd write 48*0.5*(9+4) over here and it would be quite fine] because that's how PC's do it and there's little to imply otherwise...

Seen it done in academia even... which means the rule that x = everything after the "/" is not as world wide spread a rule as you assume it must be because that's what you where taught... while others have obviously been taught that "/" only implies division and not fractions.

Math itself applies to everything, the symbols used in math on the other hand are still not 100% standardised it seems.


Of course i could be wrong, but to prove that it would require someone with knowledge of math symbol standards all over the world and the history of math symbols....
 

Joseph Webb

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drdamo said:
Ok lets simplify:

48 = A
2 = B
9+3 = C

So now we have A/B*(C)
As you can see I haven't changed anything, I simply renamed the numbers.

In short this will become:

48 / 2 * 12 = 288

And btw:

A/B*(C) = (A/B)*(C)

Because both have the same order of operations: Devide first & Multiply second and since both have an equal priority the result goes from left to right like it has always been.

The answer will only be 2 if its written like: A/(B*(C))

Why? Because in order to change the order, when both operations have the same priority, you have to bracket the one who's priority needs to change and therefore make an exception on the left-to-right rule.

Saying (9+3) is part of the denominator is an assumption and not based on the facts that are our order of operations.
You're wrong. You've never had to reduce lengthy equations, have you? You've never used the distributive property, have you? I didn't think so. Go google the order of operations real quick, and you'll soon find the error of your ways. I'd also look up the distributive method if I were you.
 

yeel

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Joseph Webb said:
mps4li3n said:
Pontus Hashis said:
The thing is, our teacher told us that multiply and divide comes befor subtraction and addition, but not which comes first, but not which of multiplying or dividing is first... but now I know, and knowing is half the battle!
Because neither does... 48/2 is the same as 48*0.5, if you know that you don't need to have any come first...

The issue here is that it's not clear if the fraction is 48/2 or 48/2(9+3). And obviously people have been taught both variations.
There is no variation, the question is very clear. The question states 48/2(9+3). The answer is 2. The question does not state (48/2)(9+3), which would equal 288. The problem here is that people don't understand fractions. 48 is the numerator, 2(9+3) is the denominator. Please do not provide answers when you don't actually know what it is.
An interesting point Joseph Webb. I do feel there is seems to be a variations in how people interpret the divide sign. Some people believe

1/2 * 1/2 = 1/4

While you would be prone to interpret this as:

1
--------- = 1
2 * (1/2)

especially if i left out the spaces and wrote it down instead like: 1/2*1/2

You also seem not to like people posting on this topic who you deem not to understand fractions as well as you do.
 

Joseph Webb

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mps4li3n said:
Joseph Webb said:
mps4li3n said:
DemiGodEpsilon said:
Uhh.. not really. If you passed 5th grade math, you'd know the answer is 2.
Sarcasm, the only thing less understood then this equation.


Joseph Webb said:
You see, there's the flaw in your logic. We are not computers. It doesn't not matter how it is written for us, you should understand that (48/2)(9+3) =/= 48/2(9+3) The fact that you think that they are equal proves to me that you do not understand the distributive property. Stop arguing with your flawed logic, you will never be correct, because we will never be computers. Computers are provided with a flawed logic system in their programming, every math teacher (and decent math student) knows this.

But the thing is that in the end the symbols used and what they mean are wholly artificial and arbitrary... it really doesn't matter if 48 was writen as $* or kanji as long as it meant the same 48 pieces of whatever.


And because both variations exist in the real world the 1st question to ask is "üsing what system, the computer's or the one you know from studying math".

Problem is that no one bothered to ask that and that's why we're on page 16+
You're either a troll, or you just don't understand the situation. Do you understand how calculators work? Do you understand the flaw in their logic when calculating a problem like that? This is seriously a basic 8th grade problem that teachers use to screw up their students (and hopefully use it to teach them a lesson the won't forget about the distributive property and how their calculators are retarded). The answer is 2. If you're using the flawed logic of a calculator to solve the problem, the answer is 288. However, that answer is wrong. To type the same question into the calculator, you need to work around its flawed logic by including an additional set of parentheses. The problem you would plug into a calculator would be 48/(2(9+3)), which equals 48/2(9+3), which equals 2. The thread starter is probably a troll, because you have to have failed pre-algebra to not understand that calculators are flawed. Seriously.

Oh for crying out loud...

You might have been taught that "/" is only ever

1
---
x

with x = everything after the "/" , but not everyone was... some people only saw "/" on the computer and they assumed it simply means divided by [ 48:2x(9+4) is how we'd write 48*0.5*(9+4) over here and it would be quite fine] because that's how PC's do it and there's little to imply otherwise...

Seen it done in academia even... which means the rule that x = everything after the "/" is not as world wide spread a rule as you assume it must be because that's what you where taught...

Math itself applies to everything, the symbols used in math on the other hand are still not 100% standardised it seems.


Of course i could be wrong, but to prove that it would require someone with knowledge of math symbol standards all over the world and the history of math symbols....
No dude, you're wrong. / always implies a fraction, yes, ALWAYS. / does not always imply that EVERYTHING following it is a fraction. 1/2+1 = 3/2, it does not equal 1/3. You aren't as aware of how to write out math as you think you are if you really think that there's any GOOD reason you can get this question wrong.
 

Joseph Webb

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yeel said:
Joseph Webb said:
mps4li3n said:
Pontus Hashis said:
The thing is, our teacher told us that multiply and divide comes befor subtraction and addition, but not which comes first, but not which of multiplying or dividing is first... but now I know, and knowing is half the battle!
Because neither does... 48/2 is the same as 48*0.5, if you know that you don't need to have any come first...

The issue here is that it's not clear if the fraction is 48/2 or 48/2(9+3). And obviously people have been taught both variations.
There is no variation, the question is very clear. The question states 48/2(9+3). The answer is 2. The question does not state (48/2)(9+3), which would equal 288. The problem here is that people don't understand fractions. 48 is the numerator, 2(9+3) is the denominator. Please do not provide answers when you don't actually know what it is.
An interesting point Joseph Webb. I do feel there is seems to be a variations in how people interpret the divide sign. Some people believe

1/2 * 1/2 = 1/4

While you would be prone to interpret this as:

1
--------- = 1
2 * (1/2)

especially if i left out the spaces and wrote it down like: '1/2*1/2'

You also seem not to like people posting on this topic who you deem not to understand fractions as well as you do.
I'll be really honest with you, that is the stupidest thing I've ever heard. You don't understand a bit of what I'm saying. THE DISTRIBUTIVE METHOD, DO YOU KNOW WHAT IT IS? If the question were written 1/2(1/2), then the answer would, indeed, be one. Unfortunately, you don't understand mathematical notation.

I'm sorry my posts are getting heated, but seriously, I took math for like, 10 years straight. I had this kind of thing drilled into my head. I know when I'm right.
 

drdamo

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I aced my equations exam as the only in my summerclass and since then I haven't been pointed out that I'm wrong. And I have to do a fair ammount of equations being an environmental science student and all, so if you have a different opinion I respect that, but don't think I'll "see the error of my ways" when a total stranger says so, compared to a school filled with teachers who give me the thumbs up for my work.
 

mps4li3n

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Apr 8, 2011
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yeel said:
Joseph Webb said:
mps4li3n said:
Pontus Hashis said:
The thing is, our teacher told us that multiply and divide comes befor subtraction and addition, but not which comes first, but not which of multiplying or dividing is first... but now I know, and knowing is half the battle!
Because neither does... 48/2 is the same as 48*0.5, if you know that you don't need to have any come first...

The issue here is that it's not clear if the fraction is 48/2 or 48/2(9+3). And obviously people have been taught both variations.
There is no variation, the question is very clear. The question states 48/2(9+3). The answer is 2. The question does not state (48/2)(9+3), which would equal 288. The problem here is that people don't understand fractions. 48 is the numerator, 2(9+3) is the denominator. Please do not provide answers when you don't actually know what it is.
An interesting point Joseph Webb. I do feel there is seems to be a variations in how people interpret the divide sign. Some people believe

1/2 * 1/2 = 1/4

While you would be prone to interpret this as:

1
--------- = 1
2 * (1/2)

especially if i left out the spaces and wrote it down like: '1/2*1/2'

You also seem not to like people posting on this topic who you deem not to understand fractions as well as you do.

He's doing the same thing the people that say it's 228 are, assuming that because his education system uses a sign in a distinct way all others must do the same, just because math itself is the same...

But the symbols aren't math themselves, they're just as arbitrary as any writing system... which is why the same symbol can be interpreted differently based on your region of the world.



And they're also prone to change, especially if something like computers, which are very popular, uses them differently the new way can replace the old one... which is also why we don't speak the same language as our ancestors from 2000 years ago... math is just more insular and changes harder then speech, but it isn't immune. But that's besides the point.
 

RonHiler

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He's doing the same thing the people that say it's 228 are, assuming that because his education system uses a sign in a distinct way all others must do the same, just because math itself is the same...

But the symbols aren't math themselves, they're just as arbitrary as any writing system... which is why the same symbol can be interpreted differently based on your region of the world.
Indeed.

I'll allow that the answer is 2 if you want to interpret the symbol "/" that way. But I'd argue that's not a common interpretation any more (if it ever was). Everyone I know would interpret that answer as 288, because they consider the / to be defined as "Divided by". the same way * is interpreted as "multiplied by" with the same precidence. But then, I hang around with computer programmers all day long, so perhaps my view is skewed in that direction more than most.
 

Joseph Webb

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drdamo said:
I aced my equations exam as the only in my summerclass and since then I haven't been pointed out that I'm wrong. And I have to do a fair ammount of equations being an environmental science student and all, so if you have a different opinion I respect that, but don't think I'll "see the error of my ways" when a total stranger says so, compared to a school filled with teachers who give me the thumbs up for my work.
If your answer was 288, then you're wrong. http://www.purplemath.com/modules/orderops2.htm There's a link as to why, maybe it'll help you understand the error of your ways. It doesn't even include /difficult topics/ like the distributive method. REMEMBER, the division symbol they use is the EXACT same as the / symbol. Scroll down until you see them solve Simplify 16 ÷ 2[8 ? 3(4 ? 2)] + 1. that problem. It EVEN states how calculators solve these types of problems incorrectly! AMAZING!
 

mps4li3n

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Joseph Webb said:
No dude, you're wrong. / always implies a fraction, yes, ALWAYS. / does not always imply that EVERYTHING following it is a fraction. 1/2+1 = 3/2, it does not equal 1/3. You aren't as aware of how to write out math as you think you are if you really think that there's any GOOD reason you can get this question wrong.
I'm quite aware how we write math HERE... just because there's one math doesn't mean there aren't multiple way to write it and that no one has different symbols for the operations...

As you pointed out, we're not computers, we don't have standardised programs that run us, and math didn't just appear in one place and everyone just followed some sacred law about what symbol means what...


It's the same thing with using the metric system... it's a standard that not everyone is using, doesn't mean they're not measuring the same thing... and just because you only ever heard of the metric system doesn't mean there aren't others.

Yes, math symbols aren't that different as m vs ft, but that doesn't mean there's no variation at all on the entire planet, remember that until pretty recently travel to the other side of the world wasn't a matter of hours.
 

Taerdin

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Pyro Paul said:
the answer is 2.

2(9+3) is the simplified form of 2*9 + 2*3
NOT
2 * (9+3)

as written the equation should be seen as
48 / (2*9 + 2*3)

which when calculated out equials 2.
You're forgetting your BEDMAS/PEMDAS. You have to do the division before the multiplication, from left to right.

48/2 = 24

24 * 9 + 24 * 3 = 288

You should do some review on order of operations
 

Joseph Webb

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RonHiler said:
He's doing the same thing the people that say it's 228 are, assuming that because his education system uses a sign in a distinct way all others must do the same, just because math itself is the same...

But the symbols aren't math themselves, they're just as arbitrary as any writing system... which is why the same symbol can be interpreted differently based on your region of the world.
Indeed.

I'll allow that the answer is 2 if you want to interpret the symbol "/" that way. But I'd argue that's not a common interpretation any more (if it ever was). Everyone I know would interpret that answer as 288, because they consider the / to be defined as "Divided by". the same way * is interpreted as "multiplied by" with the same precidence. But then, I hang around with computer programmers all day long, so perhaps my view is skewed in that direction more than most.
Listen to me, the ÷ symbol means the EXACT same thing as the / symbol. THEY BOTH MEAN DIVIDE. Dividing is setting up a fraction. You don't understand this, because you didn't pass math in the 8th grade. I'm not even kidding, I knew that ÷ and / both meant divide since the fourth grade. Math means the same thing everywhere, how do you think calculus was discovered in two different parts of the world at the same time? How do you think that algebra was discovered by a middle eastern man, and taught to europeans?
 

Joseph Webb

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Taerdin said:
Pyro Paul said:
the answer is 2.

2(9+3) is the simplified form of 2*9 + 2*3
NOT
2 * (9+3)

as written the equation should be seen as
48 / (2*9 + 2*3)

which when calculated out equials 2.
You're forgetting your BEDMAS/PEMDAS. You have to do the division before the multiplication, from left to right.

48/2 = 24

24 * 9 + 24 * 3 = 288

You should do some review on order of operations
YOU are forgetting your PEMDAS. 48/2(9+3) is a simplified version of 48/(9(2)+3(2)). Ask any math teacher or student, you are doing it wrong.
 

Joseph Webb

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mps4li3n said:
Joseph Webb said:
No dude, you're wrong. / always implies a fraction, yes, ALWAYS. / does not always imply that EVERYTHING following it is a fraction. 1/2+1 = 3/2, it does not equal 1/3. You aren't as aware of how to write out math as you think you are if you really think that there's any GOOD reason you can get this question wrong.
I'm quite aware how we write math HERE... just because there's one math doesn't mean there aren't multiple way to write it and that no one has different symbols for the operations...

As you pointed out, we're not computers, we don't have standardised programs that run us, and math didn't just appear in one place and everyone just followed some sacred law about what symbol means what...


It's the same thing with using the metric system... it's a standard that not everyone is using, doesn't mean they're not measuring the same thing... and just because you only ever heard of the metric system doesn't mean there aren't others.

Yes, math symbols aren't that different as m vs ft, but that doesn't mean there's no variation at all on the entire planet, remember that until pretty recently travel to the other side of the world wasn't a matter of hours.
You are a troll. If you aren't, you are very uneducated. There are no two ways about it. Math is the same everywhere. Even in North Korea.
 

mps4li3n

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Joseph Webb said:
drdamo said:
I aced my equations exam as the only in my summerclass and since then I haven't been pointed out that I'm wrong. And I have to do a fair ammount of equations being an environmental science student and all, so if you have a different opinion I respect that, but don't think I'll "see the error of my ways" when a total stranger says so, compared to a school filled with teachers who give me the thumbs up for my work.
If your answer was 288, then you're wrong. http://www.purplemath.com/modules/orderops2.htm There's a link as to why, maybe it'll help you understand the error of your ways. It doesn't even include /difficult topics/ like the distributive method. REMEMBER, the division symbol they use is the EXACT same as the / symbol. Scroll down until you see them solve Simplify 16 ÷ 2[8 ? 3(4 ? 2)] + 1. that problem. It EVEN states how calculators solve these types of problems incorrectly! AMAZING!
And you're right... IN AMERICA (or where that's from).

It's not impossible that in other places they might use the symbols differently... or perhaps standardisation was actually reached the whole globe and everyone uses it like that... my point was that i don't have enough knowledge to say either way... the question is do you?



And obviously you didn't read the whole link:

"" The general consensus among math people is that "multiplication by juxtaposition" (that is, multiplying by just putting things next to each other, rather than using the "×" sign) indicates that the juxtaposed values must be multiplied together before processing other operations. But not all software is programmed this way, and sometimes teachers view things differently. If in doubt, ask!""


But you're right, 2 seems to be the number the consensus favours... so what?


Joseph Webb said:
You are a troll. If you aren't, you are very uneducated. There are no two ways about it. Math is the same everywhere. Even in North Korea.
Really, so you really think that the Ancient Sumerians used the same symbols we do?! Or the Ancient Egyptians?

Math is math, symbols are not math, just representations... and one should never assume that they always represent the same thing no matter where they're used, like math does.

I know i'm not good at making my point be crystal clear, especially since this is not my native language, but do try to take a step back and see what i'm saying.