# 48÷2(9+3) = ???

Discussion in 'Bad Dog Cafe' started by Agave_Blue, Apr 9, 2011.

## 48÷2(9+3) = ???

190 vote(s)
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1. ### megafiddleFormer Member

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Multiplication and division have equal precedence.
Those two are evaluated from left to right.

2. ### BrendoTele-Holic

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288. Division and multiplication are equal. IN Australia we learned BIMDAS (Brackets, Indices, Multiplication, Division, Addition Subtraction) and that the M & D were equal and the A & S were equal. So then it comes into the order that they appear in (left to right).

48 / 2 (9 + 3) should be written as 48 / 2 x (9 + 3) which becomes 48 / 2 x 12 which becomes 24 x 12 which is 288.

The argument for 2 (9 + 3) being a single 'unit' and hence requiring calculation first doesn't seem right. What calculation is being done between the 2 and the (9 + 3)? It's multiplication, so it fits back into the BIMDAS rules.

Happy to be wrong, and this still hasn't made me play any better.

3. ### elicrossPoster Extraordinaire

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Oh.

How am I gonna tell Aunt Sally?

4. ### TdotPoster Extraordinaire

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Much easier on a Mac, only two keys and one hand (actually I just use my thumb), to make the ÷ symbol.
[option]+[/]

Since the original expression shows the 2 "attached" to the parenthesis, it is part of that value, not independent, not part of the 48.

You can play with your calculators and anagrams but the answer is 2.

If you want the answer to be 288 you have to change the formula to include a multiplication symbol.

48÷2x(9+3)=288
24x12=288

The original
48÷2(9+3)=2
48÷24=2

Suppose you move the 2?

it would still be
48÷(9+3)2=?
48÷24=2

Applying the 288 theory (making "2" and "9+3" independent values) would give you...
48÷(9+3)2=?
48÷12x2=?
4x2=8

5. ### getbentTelefiedSilver Supporter

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if that is the case, why ask it as a question in your original post?

If you are absolutely certain of the outcome, how could it be a question?

6. ### chezdeluxePoster Extraordinaire

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What if was an instance of (9+3)/2 or (9+3)/3 or (9+3)squared or (9+3)cubed. How would you treat that? You would perform all the operations associated with the bracket first wouldn't you?

7. ### jbmandoPoster ExtraordinaireGold Supporter

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Well there's no reason to write it as (9+3) unless you are supposed to multiply that sum by 2. If they want it to be 288 and unambiguous, there are some ways to write it that clear it right up:

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

Otherwise, it's going to be 2 for anybody whose graduated in the last millennium.

8. ### emu!Poster Extraordinaire

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I made As in algebra...it's 2.

If it's not 2, I'll eat my shoe.:neutral:

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10. ### jbmandoPoster ExtraordinaireGold Supporter

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Well, if they're really teaching algebra the way they are talking about it on the internet today, it's 288. I just can't believe they are teaching it that way. PEMDAS then left to right with mult. and div. treated equally does yield 288, but I am absolutely sure that I was taught that the 2(9+3) was treated as a complete operation first, then the division is done.

11. ### otterhoundPoster Extraordinaire

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Now: How many licks does it take to get to the Tootsie Roll center of a Tootsie Pop?[/QUOTE]
3 . I remember the ad on TV .

12. ### Hack On WheelsTele-Meister

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"Proximity" is an invalid argument. 2(9+3) contains an implied multiplication symbol. When a term is in brackets it is acknowledged as a separate entity and unless otherwise noted it is to be multiplied in the context of the equation. It can be re-written as 48÷2*(9+3) and then solved with brackets and then multiplication/division from left to right.

That being said, I never leave these things up to chance and I use brackets quite excessively. This is an evil "question" as it reveals how mathematics are taught inconsistently.

Well said! This is one of the easier to follow explanations.

13. ### Agave_BlueFriend of Leo's

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14. ### Colt W. KnightDoctor of TeleocityAd Free Member

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3 . I remember the ad on TV .[/QUOTE]
That is misleading because that damned owl bit that tootsie pop!

15. ### Guitar_NinjaFriend of Leo'sAd Free Member

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I'd be inclined to reevaluate this as a trig problem, considering how obtuse you're being.

Unfortunately in algebra there's nothing miscellaneous about brackets. Used to clarify terms in algebraic equations.

The calculators in question enter terms in different ways. Depending on which terms you wish to evaluate, you must enter the equation in a specific format.

If you wish to evaluate the product of 48 divided by the sum of 9 plus 3 multiplied by two, then you enter it one way. If you wish to evaluate the product of 48 divided by two, multiplied by the sum of 9+3 then you enter it another way. That other way will be dependent on the programming of the device being used.

If you don't know what you're trying to solve for when you enter the equation into the calculator then there is no answer.

Garbage In, Garbage Out.

16. ### getbentTelefiedSilver Supporter

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When I start threads, I find things that I think would be interesting to discuss, but I also go find out what it is about so that I can take some responsibility for it....

17. ### Agave_BlueFriend of Leo's

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All true (well, except maybe that obtuse bit).

But, what I'm saying is the problem is posed as it is posed. I cannot provide context; it is posted as I found it.

If one chooses to add additional symbols, they've redefined the problem - without the context you allude to. IOW, they've redefined the problem to suit their particular preference for what they believe the solution is.

I say, that the addition of symbols is not necessary; that the rules of arithmetic are all that is needed to solve the problem as written.

However, again, I do agree that if one wanted to ask this question (or explain their basis for a solution) in an unambiguous fashion - avoiding possible misinterpretation - it could, and should, be written more clearly.

18. ### BreenFriend of Leo's

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I think its 2. I really need to study basic math again.
But as I read the replies, and re-writing the equation to 48 / 2 (9+3), its 288. Darn it.

Come on, where are the NASA engineers and MIT mathematicians on TDPRI? I KNOW your lurking somewhere.

19. ### Agave_BlueFriend of Leo's

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I said, "It's not 'my' question". As in I don't own it; I did not create it.

I never said it wasn't my thread. I am responsible for this thread. If it is uninteresting, why are there 2 pages and however many poll participants?

If I'm the first person who has cross-pollinated a topic here, I'll be shocked.

If you think it's inappropriate, you have the power and prerogative to pass judgement.

20. ### rcole_soonerPoster Extraordinaire

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2.

Parens first, mult next, then divide.

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