48÷2(9+3) =

[dullard]

That is very sloppy and complicates things

So is leaving out the "*", but you seem to have no problem with that.

 

[Paul98]

So is leaving out the "*", but you seem to have no problem with that.

Because it isn't and does not complicate things at all and is standard notation. There is zero confusion what is meant when I write 2a, or write (13x+1y)(x+2y), or 3(12x + y),...

http://en.wikipedia.org/wiki/Special_relativity
http://en.wikipedia.org/wiki/Calculus

look at equations, looks like standard notation to me.

 

[DisgruntledVirus]

That is very sloppy, and complicates things especially when you want to have more stuff after the / that isn't the denominator. If I write 1/2 + 3 it should mean exactly what it says, I should not have to figure out if something is implied or not.

That's 1/5 right?

 

[Paul98]

That's 1/5 right?

hahahaha, looks like half the people in here think it should be

 

[busydude]

That's 1/5 right?

Not sure if serious.

 

[purbeast0]

That's 1/5 right?

duh ... implied parenthesis.

 

[HumblePie]

I can see the whole argument stems from the long form division versus short form.

Basically people getting 2 for the answer and saying "implied parens" are seeing the equation as this.

       48
--------------
    2(9+x3)

which is equivalent to

 48             1
----    x    -----
  2           (9+3)

Which would be 2

However that is not how the term was written. You can not state that long form equals short form math. To correctly get 2 as the answer for a short form you HAVE to use brackets or another set of parens. There is no such thing as implied parens in math. so the equation 48/2(9+3) = 288

That is because of it being written in short form. To make the answer 2 one must use additional brackets like this 48/[2(9+3)] = 2 as that is correct way to use make this equal to a long form notation of what I posted originally. Otherwise the long form version of the OP equation is..

 48
---- (9+3)
  2

or 

 48
---- x (9 + 3)
  2

So that is why the answer is 288.

 

[dullard]

Because it isn't and does not complicate things at all and is standard notation. There is zero confusion what is meant when I write 2a, or write (13x+1y)(x+2y), or 3(12x + y),...

http://en.wikipedia.org/wiki/Special_relativity
http://en.wikipedia.org/wiki/Calculus

look at equations, looks like standard notation to me.

The first link includes symbols, not just numbers. The second link had this: "Force = Mass × acceleration" and this: "distance = speed · time". Notice the use of proper multiplication symbols.

Please show one link where you can leave out the multiplication sign properly when a formula is in numbers.

Clearly x = 23, means x=6 since I left out the multiplication sign. As you say, that is common writing to leave it out. Clearly x=2(3) is not a 2^3 or x=2 with a footnote #3, etc. Again, you clearly know that, right? Clearly x=f(2) means to multiply f by 2 and not the function f(2).

Clearly, the nearly 50 - 50 tie of the poll in this thread shows that your usage isn't confusing. No one at all could mess it up!

 

[GundamW]

hahahaha, looks like half the people in here think it should be

Actually, I am not that surprised given how the US education system currently is....

With this math thread, the many gun threads, and how ATOT value human life (from the "stealing car" thread), I think we will be reverting back to the Old West lifestyle pretty soon.....

 

[novasatori]

This thread gets better and better.

 

[airdata]

and... apprximately 99.999% of forum members have no need for such math skills in their daily lives.

 

[Paul98]

The first link includes symbols, not just numbers. The second link had this: "Force = Mass × acceleration" and this: "distance = speed · time". Notice the use of proper multiplication symbols.

Please show one link where you can leave out the multiplication sign properly when a formula is in numbers.

Clearly x = 23, means x=6 since I left out the multiplication sign. That is common writing to leave it out. Clearly x=2(3) is not a 2^3 or x=2 with a footnote #3, etc. Again, you clearly know that, right?

Ofcourse they use x or *,... when you have numbers like 2*3. It's not to say that you can't use * or x,... But it is commonly used that something like 2a, or 2(2+4), is the same thing as writing 2*a or 2*(2+4). And writing it one way or the other won't change anything. And are just as clear.

as for the first link not using actual numbers, scroll down to classical limit.

 

[Beev]

Hahahahahahahahahahahahahaha! I haven't been in this thread since it was first posted, but I just looked at the poll results and LOL @ all of the votes for 2. Ridiculous. Those of you that voted 2 are bad and should feel bad.

 

[dullard]

Ofcourse they use x or *,... when you have numbers like 2*3... And are just as clear.

Why use a x or * if it is just as clear without it? x = 23 means x=6. Just as clear, since you say so.

 

[Paul98]

Clearly, the nearly 50 - 50 tie of the poll in this thread shows that your usage isn't confusing. No one at all could mess it up!

I said it before, and I'll say it again, you did this:
48 / 2 * (9 + 3)
The OP did this:
48 / 2 (9 + 3)
There is a big difference. I don't have Python, but every other math program I have spits out undefined or mentions an error. The error is the lack of the multiplication sign. 2 and 288 are both wrong because that isn't a formula that you can evaluate.

This isn't an order of operations issue. It is a lack of properly defined operations issue. There is no order when the equation isn't an equation. Those giving an answer are as wrong as those giving the "incorrect" answer.

* Excel says "Microsoft Excel found an error in the formula you entered".
* Matlab says "Unbalanced or unexpected parenthesis or bracket".
* Google converts it to an equation it can handle in some cases, but it doesn't in most cases. For example Google won't work if you do this: "2 (12) ="
* MathCad says "This variable or function is not defined above".
* Visual Basic says "Compile error: Expected: end of statement".

But I thought you were arguing that you have to use the * or it doesn't make any sense and you can't evaluate the equation. You seem to be in the 2% that voted ?

 

[Paul98]

Why use a x or * if it is just as clear without it? x = 23 means x=6. Just as clear, since you say so.

no where did I ever say that you could do that, and it doesn't make any sense. But that's all I will say to you if you don't think 2(9+3) is a common notation for 2*(9+3) even with given links, and multiple high level math books. Your mind is made up and there is no way to convince you.

 

[RedCOMET]

This thread is full of fail. EPIC FAIL!

 

[blurredvision]

Good lord, when are you people going to learn that those who voted 2 simply did so in order to troll after seeing the first 30 posts of this thread? I know I did. I guess I should be pleased that it's worked so brilliantly, but this thread and its subsequent spin-offs are getting a little ridiculous.

 

[HumblePie]

Good lord, when are you people going to learn that those who voted 2 simply did so in order to troll after seeing the first 30 posts of this thread? I know I did. I guess I should be pleased that it's worked so brilliantly, but this thread and its subsequent spin-offs are getting a little ridiculous.

Some did so because they don't know proper short form notation and order of precedence. Then again this is a nerd forum and nerds argue over nerd crap like this constantly. If you aren't a nerd you need to find another forum to use. 4 chan might be your speed.

 

[airdata]

From physicsforum.com user RJS

Re: 48÷2(9+3)

Looking at it like this though:


48 ÷ x(9 + 3) = 288
48 ÷ 9x + 3x = 288
48/12x = 288
4/x = 288
4 = 288x
4/288 = x
1/72 = x


Would suggest that 288 is wrong, and that 2 is correct.


Also, with the order of operations aren't we using the distributive property which states as an example:


Simplify 16 ÷ 2[8 – 3(4 – 2)] + 1.
16 ÷ 2[8 – 3(4 – 2)] + 1
= 16 ÷ 2[8 – 3(2)] + 1
= 16 ÷ 2[8 – 6] + 1
= 16 ÷ 2[2] + 1 (**)
= 16 ÷ 4 + 1
= 4 + 1
= 5


Then, looking at what I have bolded below:



The confusing part in the above calculation is how "16 divided by 2[2] + 1" (in the line marked with the double-star) becomes "16 divided by 4 + 1", instead of "8 times by 2 + 1". That's because, even though multiplication and division are at the same level (so the left-to-right rule should apply), parentheses outrank division, so the first 2 goes with the [2], rather than with the "16 divided by". That is, multiplication that is indicated by placement against parentheses (or brackets, etc) is "stronger" than "regular" multiplication. Typesetting the entire problem in a graphing calculator verifies this hierarchy.

Note that different software will process this differently; even different models of Texas Instruments graphing calculators will process this differently. In cases of ambiguity, be very careful of your parentheses, and make your meaning clear. 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!

This all seems to point toward 2 being the correct answer.

 

[DrPizza]

I said it before, and I'll say it again, you did this:
48 / 2 * (9 + 3)
The OP did this:
48 / 2 (9 + 3)
There is a big difference. I don't have Python, but every other math program I have spits out undefined or mentions an error. The error is the lack of the multiplication sign. 2 and 288 are both wrong because that isn't a formula that you can evaluate.

This isn't an order of operations issue. It is a lack of properly defined operations issue. There is no order when the equation isn't an equation. Those giving an answer are as wrong as those giving the "incorrect" answer.

* Excel says "Microsoft Excel found an error in the formula you entered".
* Matlab says "Unbalanced or unexpected parenthesis or bracket".
* Google converts it to an equation it can handle in some cases, but it doesn't in most cases. For example Google won't work if you do this: "2 (12) ="
* MathCad says "This variable or function is not defined above".
* Visual Basic says "Compile error: Expected: end of statement".

Equation? Are you the first person in this thread to call that expression an equation?

 

[airdata]

From : http://www.mathway.com

Problem:

http://www.mathway.com/login.aspx?p=calg?p=48SMB142(9+3)?p=2?p=?p=?p=?p=?p=?p=?p=0?p=?p=

Answer:

2

 

[HumblePie]

From : http://www.mathway.com

Problem:

http://www.mathway.com/login.aspx?p=calg?p=48SMB142(9+3)?p=2?p=?p=?p=?p=?p=?p=?p=0?p=?p=

Answer:

2

Again, read my post above. The problem is you are reading the short form incorrectly in long form notation.

48/2(9+3)

=/=

   48
-------
2(9+3)

It is instead.

48/2(9+3)

==

 48
---- (9 + 3)
  2

 

[DisgruntledVirus]

From physicsforum.com user RJS

Replacing 2 with an x changes the equation. In order to find out the value of x, you have to follow a different order of operations than you do to evaluate the expression posed in the OP.

 

[DrPizza]

Here, maybe this will help. I'm going to point out, as matthiasa and a couple others have, that this isn't a rule; simply something that's generally agreed upon:

(ignore the top line)