

Solve this equation > 48÷2(9+3) = ? 
View Poll Results: Which is right?  
2  663  55.76%  
288  526  44.24%  
Voters: 1189. You can't vote on this poll right now  are you signed in? 

Thread Tools  Search this Thread 
09042011, 15:35  #176 
Forum Member
Join Date: May 2008
Location: Slaving over a hot laptop
Posts: 3,672

deleted  duplicate post

Please sign in or register to remove this advertisement.

09042011, 15:39  #177 
Forum Member
Join Date: Jan 2011
Location: London
Posts: 1,333

Quote:
I have. What's inside the brackets is 9 + 3 which is 12.
No. I don't know where you're getting that from but it isn't right. There is no such rule. 
09042011, 15:40  #178 
Forum Member
Join Date: Jul 2003
Location: Freezing 20ēC wind chill
Posts: 10,595

Quote:
which would give
48 ÷ 2*9 + 2*3 = neither 288 or 2 a) 2 48  18 + 6 or b) 8.66 (recurring) 48  + 6 18 Of course I would go with b but unless written in long form it still leaves some potential ambiguity. 
09042011, 15:40  #179 
Guest
Join Date: Sep 2010
Posts: 2,519

It's 288.

09042011, 15:47  #180 
Forum Member
Join Date: May 2008
Location: Slaving over a hot laptop
Posts: 3,672

Quote:
But that's still short form is the sum:
a) 2 48  18 + 6 or b) 8.66 (recurring) 48  + 6 18 Of course I would go with b but unless written in long form it still leaves some potential ambiguity. Although as I wrote it there could be a third version 48  *9 + 2*3 = 24 * 9 + 2*3 = 216 + 6 = 222 2 
09042011, 15:48  #181 
Forum Member
Join Date: May 2009
Posts: 11,755

Quote:
It's 288.

09042011, 15:51  #182 
Guest
Join Date: Feb 2010
Posts: 8,596

No No!!
I keep looking at this thread and I know every time I come in it'll still be: It's 2 no it's 288 I just can't stand it!! I want to know what the right answer is.. Stamps feet. can we not just ask the person who made all these things up? For some reason this is driving me nuts. 
09042011, 15:51  #183 
Forum Member
Join Date: Mar 2007
Location: Hampshire
Posts: 5,971

Quote:
Maybe older posters who were taught in school to do it from left to right are getting 288, whereas those younger like myself, who were taught the bodmas method are getting 2?
How would those who get 288 do this: 48÷2(x+y) ? Or this: 48 divided by 2(9+3) (which is what it says, verbatim, in the OP)? To rationalise to 288, it would read (48÷2)(9+3). 
09042011, 15:52  #184 
Forum Member
Join Date: Nov 2003
Location: Norwich, Norfolk, UK
Posts: 13,294

Quote:
the lack of multiplication sign next to the bracket means that the 2 is affixed to it and therefore should be timsed before the 48 even comes into it because of BODMAS.
BODMAS says calculate what is inside brackets first. Then powers. Then division and multiplication equally working left to right. Finally addition and subtraction equally working left to right. 2(9+3) is calculated in exactly the same way as 2 x (9+3) in every sense. Whether the multiplication sign is there or not has absolutely no effect. It is very poor notation to omit the multiplication sign when using a number before the bracket but it doesn't change how it should be calculated. 
09042011, 16:07  #185 
Forum Member
Join Date: Jan 2011
Location: London
Posts: 1,333

To the above poster, I'm going to try something
So we've established that it varies by opinion, but what is 48÷2x(9+3)? Does your answer change? 
09042011, 16:12  #186 
Forum Member
Join Date: Jun 2007
Location: Alba
Posts: 8,127

debate still underway ... seems calculators can come up with different views too!!

09042011, 16:14  #187 
Forum Member
Join Date: Mar 2008
Posts: 190

Did this in school for GCSE's and I'm currently redoing this with Open Uni for maths degree.
Writing it like this:2(9+3) is a short hand version of writing it like this: (2x9)+(2x3). Putting the 2 immediately next to the brackets is algebraic short hand for multiplying the contents of the brackets by the 2. It does not mean whack a multiplication sign in there and then work it out. The ONLY way to get 288 is if there was a multiplication sign after the 2 which there isn't . Those who think this is wrong, the solution is quite simple  put the equation into a scientific calculator verbatim and the answer is 2. End of story. 
09042011, 16:14  #188 
Forum Member
Join Date: Oct 2003
Location: The United Kingdom
Posts: 15,210

Ok  can I change camp  I no long say it is 288. In the strictest alegbraic sense.
x=48/2n n=(9+3) Therefore x=48/24 x=2 However, back in the real world, pretty much all software would assume the answer to be 288. Since I write applications to report numbers for a living I have to go with 288 for the real world. Therefore the answer is either, depending if you deal in abstract or if you deal in reality. Can we have this third option added to the poll 
09042011, 16:14  #189 
Forum Member
Join Date: Nov 2007
Location: London
Posts: 100

48÷2(9+3)  in this equation the answer is 2. You do the brackets first  getting (2x12) which is 24. 48/24 is 2.
(48÷2)(9+3)  in this equation the answer is 288. You do the brackets first and so get 24 x 12=288. 
09042011, 16:14  #190 
Forum Member
Join Date: Jan 2011
Location: London
Posts: 1,333

Quote:
Did this in school for GCSE's and I'm currently redoing this with Open Uni for maths degree.
Writing it like this:2(9+3) is a short hand version of writing it like this: (2x9)+(2x3). Putting the 2 immediately next to the brackets is algebraic short hand for multiplying the contents of the brackets by the 2. It does not mean whack a multiplication sign in there and then work it out. The ONLY way to get 288 is if there was a multiplication sign after the 2 which there isn't . Those who think this is wrong, the solution is quite simple  put the equation into a scientific calculator verbatim and the answer is 2. End of story. Much better than how I tried to explain it. 
09042011, 16:15  #191 
Forum Member
Join Date: May 2008
Location: Slaving over a hot laptop
Posts: 3,672

Quote:
To the above poster, I'm going to try something
So we've established that it varies by opinion, but what is 48÷2x(9+3)? Does your answer change? and 48÷2x(9+3) = 288 
09042011, 16:16  #192 
Forum Member
Join Date: Oct 2003
Location: The United Kingdom
Posts: 15,210

Quote:
Did this in school for GCSE's and I'm currently redoing this with Open Uni for maths degree.
Writing it like this:2(9+3) is a short hand version of writing it like this: (2x9)+(2x3). Putting the 2 immediately next to the brackets is algebraic short hand for multiplying the contents of the brackets by the 2. It does not mean whack a multiplication sign in there and then work it out. The ONLY way to get 288 is if there was a multiplication sign after the 2 which there isn't . Those who think this is wrong, the solution is quite simple  put the equation into a scientific calculator verbatim and the answer is 2. End of story. 
09042011, 16:17  #193 
Forum Member
Join Date: Nov 2003
Location: Norwich, Norfolk, UK
Posts: 13,294

Quote:
To the above poster, I'm going to try something
So we've established that it varies by opinion, but what is 48÷2x(9+3)? Does your answer change? 48÷2x(9+3) =48÷2x12 =24x12 =288 Whether the multiplication sign is present, or absent and implied by juxtaposition, has absolutely no effect, ever. 
09042011, 16:19  #194 
Forum Member
Join Date: Jun 2009
Location: near London
Posts: 790

if it's (48÷2)(9+3) its 288
if it's 48÷2(9+3) it's 2 THE answer is 42 probably 
09042011, 16:21  #195 
Forum Member
Join Date: Jan 2011
Location: London
Posts: 1,333

Quote:
It does as far as I am concerned 48÷2(9+3) = 2
and 48÷2x(9+3) = 288 My theory, anyway 
09042011, 16:21  #196 
Forum Member
Join Date: Aug 2008
Posts: 5,152

Quote:
There is no "opinion" on this amongst mathematicians. There is one unambgious standard and that gives a result of 288.
48÷2x(9+3) =48÷2x12 =24x12 =288 Whether the multiplication sign is present, or absent and implied by juxtaposition, has absolutely no effect, ever. Always do the sum inside the Brackets first. BODMAS. 
09042011, 16:21  #197 
Forum Member
Join Date: Jan 2008
Location: Earth
Posts: 2,667

This makes my head hurt.

09042011, 16:23  #198 
Forum Member
Join Date: Mar 2008
Posts: 190

OMFG!!!
The very fact that there is no sign between the 2 and the brackets means that the 2 belongs to the brackets. People need to realise that BODMAS/BIDMAS is not the only mathematical theory going on here. There is also algebra to think of. EDIT (less confusing explanation) There is no multiplication sign to be put between the 2 and the brackets. 2(9+3) does not mean 2 x (9+3). It means (2x9)+(2x3). Anyone who has successfully studied algebra will know this. 
09042011, 16:25  #199 
Forum Member
Join Date: May 2008
Location: Slaving over a hot laptop
Posts: 3,672

Quote:
Ok  can I change camp  I no long say it is 288. In the strictest alegbraic sense.
x=48/2n n=(9+3) Therefore x=48/24 x=2 Edited to add  appears to give 
09042011, 16:31  #200 
Forum Member
Join Date: Aug 2008
Posts: 5,152

Quote:
OMFG!!!
The whole reason the multiplication sign is there is because it comes immediately before the bracket. The very fact that there is no sign between the 2 and the brackets means that the 2 belongs to the brackets. People need to realise that BODMAS/BIDMAS is not the only mathematical theory going on here. There is also algebra to think of. 2x(9+3) = 18x + 6x = 24x. When you are evaluating an expression, BODMAS is the convention even in algebra. Brackets first. All you have is a multiplication symbol: 2x(9+3) = 2(9+3) = 18+6 = 24. Brackets first. Always. 
Thread Tools  Search this Thread 

All times are GMT +1. The time now is 18:57.