[AlphaK]

Originally Posted by Gneiss

No you wouldn't....

You get:

48 ÷ (18 + 6) = 48 ÷ 24 = 2

No if I have 2(a +b) and multiply out the bracket I get
2a +2b

If I had 2(9 + b) and multiply out the bracket I get
18 + 2b

You are assuming because there is ÷ operand before it that I have to solve it in other words you assume that

÷ 2(9+3) is actually ÷ ( 2 (9+3)) ie 24
and if so then
48 ÷ 2(9+3) must be 2

[Moony]

Originally Posted by HenryGarten

289 people are wrong because the correct answer is that there isn't one. You cannot solve an ambiguos problem.

Why is it ambiguous? Any more so than 5y=?

[Gneiss]

Originally Posted by AlphaK

No if I have 2(a +b) and multiply out the bracket I get
2a +2b

If I had 2(9 + b) and multiply out the bracket I get
18 + 2b

You are assuming because there is ÷ operand before it that I have to solve it in other words you assume that

÷ 2(9+3) is actually ÷ ( 2 (9+3)) ie 24
and if so then
48 ÷ 2(9+3) must be 2

I edited that post as my terminology was sloppy...

[neelia]

Originally Posted by Moony

Why is it ambiguous? Any more so than 5y=?

Because
48÷2(9+3)
is not well defined.

48÷(2(9+3)) is

(48÷2)(9+3) is

[patsylimerick]

Originally Posted by neelia

Because
48÷2(9+3)
is not well defined.

48÷(2(9+3)) is

(48÷2)(9+3) is

Bit in Bold. Without that first set of brackets, I'd always go for 2.

[Moony]

Originally Posted by neelia

Because
48÷2(9+3)
is not well defined.

48÷(2(9+3)) is

(48÷2)(9+3) is

The fact that you have to calculate the bracketed function first followed by left to right for multiplication and division operators makes the ops equation the same as your second example. If you follow the rules - its not ambiguous.

http://math.about.com/library/weekly/aa040502a.htm

[Cornucopia]

Sorry if this has already been mentioned - I haven't read the entire thread.

The problem is that the original question is not properly defined.

It could be a mathematical query, in which case, it should read:-

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

To which the answer is 2.

OR it could be for entry to a calculator, and the result would depend on whether the calculator correctly handled hanging brackets. (My phone says 288, which I think is wrong).

[Doctor_Wibble]

Originally Posted by HenryGarten

You cannot solve an ambiguos problem.

Of course you can! Simply accept that an ambiguous problem is likely to have an ambiguous answer.

So here the answer is either 2 or 288. Problem solved.

And probably something about a cat in a box.

[Shady123]

I was taught to calculate the brackets first then do the sum.

48 / 2(9+3) >>> 48 / 2(12) >>> 48 / 24 = 2

I don't understand why it would be 48 / 2 X 12 isn't the point of the brackets to show the 9+3 is only part of the right side of the equation and not a seperate part??

[Moony]

Originally Posted by Cornucopia

Sorry if this has already been mentioned - I haven't read the entire thread.

The problem is that the original question is not properly defined.

It could be a mathematical query, in which case, it should read:-

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

To which the answer is 2.

OR it could be for entry to a calculator, and the result would depend on whether the calculator correctly handled hanging brackets. (The answer is still 2).

No - because writing it the way you have implies a bracket where none was specified - i.e.

48/(2*(9+3))

[neelia]

Originally Posted by Moony

The fact that you have to calculate the bracketed function first followed by left to right for multiplication and division operators makes the ops equation the same as your second example. If you follow the rules - its not ambiguous.

In mathematical notation it is not "fact". It is ambiguous. You need the brackets to clarify it. Without the brackets it is neither my first nor second example.

You can get to

48÷2(12) but you cannot tell what you are dividing 48 by

[oldfogey101]

The answer's most definitely 2, and not 288.

You've factorized the 2 out, so in effect the 2 is inside the brackets.

[You_mo]

Originally Posted by Moony

The fact that you have to calculate the bracketed function first followed by left to right for multiplication and division operators makes the ops equation the same as your second example. If you follow the rules - its not ambiguous.

http://math.about.com/library/weekly/aa040502a.htm

I think it is. The answer is 288 but the fact SO many people are convinced otherwise indicates to me it's written a way people aren't used to.

[Moony]

Originally Posted by Shady123

I was taught to calculate the brackets first then do the sum.

48 / 2(9+3) >>> 48 / 2(12) >>> 48 / 24 = 2

I don't understand why it would be 48 / 2 X 12 isn't the point of the brackets to show the 9+3 is only part of the right side of the equation and not a seperate part??

You calculate the bracket first - then work from left to right. You have worked right to left.

[neelia]

Originally Posted by Doctor_Wibble

Of course you can! Simply accept that an ambiguous problem is likely to have an ambiguous answer.

So here the answer is either 2 or 288. Problem solved.

And probably something about a cat in a box.

nope being ambiguous means that it does not have an answer.

[You_mo]

Originally Posted by Cornucopia

Sorry if this has already been mentioned - I haven't read the entire thread.

The problem is that the original question is not properly defined.

It could be a mathematical query, in which case, it should read:-

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

To which the answer is 2.

OR it could be for entry to a calculator, and the result would depend on whether the calculator correctly handled hanging brackets. (My phone says 288, which I think is wrong).

That's the way we'd normally see it written which we'd all get the answer without quibbling!

[Moony]

Originally Posted by neelia

In mathematical notation it is not "fact". It is ambiguous. You need the brackets to clarify it. Without the brackets it is neither my first nor second example.

You can get to

48÷2(12) but you cannot tell what you are dividing 48 by

If this equation was written x/yz that would imply x/y*z. The lack of mathematical operator between 2 and (12) should be taken to imply multiplication.

[Cornucopia]

Originally Posted by Moony

No - because writing it the way you have implies a bracket where none was specified - i.e.

48/(2*(9+3))

Yes, because the division sign is after the 48, and the bracket means that the 2 belongs with the 9 and the 3.

or you can expand the brackets: 48 / (18+6) = 2

[neelia]

[quote=Moony;49326933]If this equation was written x/yz that would imply x/y*z. .[ /QUOTE]
no it would be ambiguous

The lack of mathematical operator between 2 and (12) should be taken to imply multiplication

It is not clear whther the multiplication re z operates on y ot on x/y

[Cornucopia]

Originally Posted by Moony

If this equation was written x/yz that would imply x/y*z. The lack of mathematical operator between 2 and (12) should be taken to imply multiplication.

That's ambiguous, too.

the mathematical term x/yz would be coded as x/(y*z) or even x/y/z

[Moony]

Originally Posted by Cornucopia

Yes, because the division sign is after the 48, and the bracket means that the 2 belongs with the 9 and the 3.

or you can expand the brackets: 48 / (18+6) = 2

No - you arent following the rules posted above. You always resolve whats inside the brackets first - then work left to right with whats outside.

If we go by your rules - we are taking a value outside the brackets to calculate the value within - which is wrong.

[Doctor_Wibble]

Originally Posted by neelia

nope being ambiguous means that it does not have an answer.

No, it means that there is not necessarily a single answer. Mathematics does allow the existence of multiple possible answers to a single expression so this isn't really a problem.

[Moony]

Originally Posted by Cornucopia

That's ambiguous, too.

the mathematical term x/yz would be coded as x/(y*z) or even x/y/z

No it wouldnt. Following the left to right rule it would be coded x/y * z (unless specified otherwise by the inclusion of brackets)

48/2 * 12 = 24 * 12 = 288

[neelia]

Originally Posted by Doctor_Wibble

No, it means that there is not necessarily a single answer. Mathematics does allow the existence of multiple possible answers to a single expression so this isn't really a problem.

yes if it is something like square root of 4 but that is a well defined expression. The one in the OP is not a valid mathematical expression and so there is no valid answer never mind range of answers

[oldfogey101]

Originally Posted by Moony

No - you arent following the rules posted above. You always resolve whats inside the brackets first - then work left to right with whats outside.

If we go by your rules - we are taking a value outside the brackets to calculate the value within - which is wrong.

He's right. He's not worked anything extra out. He's just rearranged some of the numbers in a perfectly valid way.