48÷2(9+3) = ???? (sound, project, photobucket, Opera)

[NJBest]

Originally Posted by infiri

Can you post them again, if it is not to much to ask...

Most certainly... here's the link to my original post:

http://www.city-data.com/forum/19285526-post110.html

[NJBest]

Originally Posted by infiri

Can you post them again, if it is not to much to ask...
but here:
National Council of Teachers of Mathematics (NCTM)
http://illuminations.nctm.org/Lesson...20operation%22

There is a certain order in which operations must be performed when evaluating expressions.
The order of operations is…
• Parentheses (or other grouping symbols)
• Exponents
• Multiplication or Division (from left to right)
• Addition or Subtraction (from left to right)

Maybe we should tell all of our math teachers they are wrong.

Originally Posted by infiri

Maybe the National Science Foundation is wrong, a federal agency.
Explaining Order of Operations - NSDL.org - The National Science Digital Library

Do all multiplications and divisions
(left to right, in the order they appear), and then
do all additions and subtractions
(left to right, in the order they appear).

So you are suggesting that all our teachers are wrong and the National Science Foundation is wrong? I think that's just plain silly, and contradicts what you have been arguing prior.

[infiri]

Originally Posted by NJBest

So you are suggesting that all our teachers are wrong and the National Science Foundation is wrong? I think that's just plain silly, and contradicts what you have been arguing prior.

dude, we are fighting about the same thing.
I was thinking you believe the correct answer is 2...
We are on the same page...

[NJBest]

Originally Posted by infiri

dude, we are fighting about the same thing.
I was thinking you believe the correct answer is 2...
We are on the same page...

Yea, I know we both feel the answer is 288... I was just saying that we have failed to show that it does. It's hard to find supporting work to show this.

I'm looking for more than just general belief... I'm looking for something solid to put it all to rest. Something that no one can argue with.

[infiri]

Originally Posted by NJBest

Yea, I know we both feel the answer is 288... I was just saying that we have failed to show that it does. It's hard to find supporting work to show this.

I'm looking for more than just general belief... I'm looking for something solid to put it all to rest. Something that no one can argue with.

Listen, let me tell you, that would never happen.
There will be always someone that thinks the sky is green and not blue.

[the_windwalker]

Example is..... 48 / 2(9+3)

Same as.... 48 / 2 * (9 + 3)
or.............. 48 / 2 * 12
and........... 48 / 24
answer...... 2

Even if I didn't remember my Algebra very well, I have Algebra software in my computer, and this is how it works it out.

[NJBest]

Originally Posted by the_windwalker

Example is..... 48 / 2(9+3)

Same as.... 48 / 2 * (9 + 3)
or.............. 48 / 2 * 12
and........... 48 / 24
answer...... 2

Even if I didn't remember my Algebra very well, I have Algebra software in my computer, and this is how it works it out.

Are you trolling or are you serious?

If you recall that division is just inverse multiplication, it would like this:

Dividing by 2 is the same as multiplying by .5.

Same as.... 48 * .5 * (9 + 3)
or.............. 48 * .5 * 12
and........... 24 * 12
answer...... 288

[infiri]

Originally Posted by the_windwalker

Example is..... 48 / 2(9+3)

Same as.... 48 / 2 * (9 + 3)
or.............. 48 / 2 * 12
and........... 48 / 24
answer...... 2

Even if I didn't remember my Algebra very well, I have Algebra software in my computer, and this is how it works it out.

Wrong....
You divide first 48/2 and then multiply by 12.

[jtur88]

x=0
∴x(x-1)=0
∴x-1=0
∴x=1
∴1=0

Re: the original OP:
It is absolutely, incontrovertibly right that the burden is on the person writing the mathematical statement to ensure that it is unambiguous. Parentheses is an available mechanism that removes ambiguity, which is why parentheses exist as a mathematical symbol. You cannot write an ambiguous statement, and then expect interpreters to agree unanimously with what you wanted them to think when you wrote it ambiguously.

[infiri]

Originally Posted by jtur88

x=0
∴x(x-1)=0
∴x-1=0
∴x=1
∴1=0

Re: the original OP:
She was absolutely, unambiguously, incontrovertibly right when she said that the burden is on the person writing the mathematical statement to ensure that it is unambiguous. You cannot write an ambiguous statement, and then expect interpreters to agree unambiguously with what you wanted them to think when you wrote it ambiguously.

You have it wrong..
x-1=0 is wrong..
X-1= -1
the original formula is not ambiguously