

Register  FAQ  Donate  Members List  Calendar  Mark Forums Read 
Bar Everything else. 
View Poll Results: 48/2(9+3) = ?  
2  72  49.66%  
288  73  50.34%  
Voters: 145. You may not vote on this poll 

LinkBack  Thread Tools 
April 8th, 2011, 02:29 AM  #27 (permalink)  
Senhor Testiculo
Join Date: Sep 2004
Location: California
Posts: 11,832

Quote:
The "2" in the original equation is not a value unto itself, it's just a quantity of (9+3). That's it. You don't divide 48 by 2, you divide it by two QUANTITIES of (9+3).
__________________
Arcana Recordings 

April 8th, 2011, 02:33 AM  #28 (permalink)  
I hate that supercow !
Join Date: Dec 2005
Location: Poland
Posts: 2,871

Quote:
Do you like how this looks ? A=10 B=20 C=30 D=40 A/B(C+D) 10/2050 Looks right to you ? It doesn't to me... 10/20*50 looks much better to me. 

April 8th, 2011, 02:40 AM  #29 (permalink) 
Senior Member
Join Date: Jun 2008
Posts: 616

Simple, order of operations guys... i think the problem here is the way you type the problem... 48/2(9+3)
1. Do parenthesis (9+3) = 11 2. Division, then Multiplication 48/2= 24 * (12) = 288 If you guys say = 2 then one would have to type problem like this.. 48/(2(9+3)) then it would be 2. 
April 8th, 2011, 02:40 AM  #30 (permalink) 
Senhor Testiculo
Join Date: Sep 2004
Location: California
Posts: 11,832

How are you ignoring this fundamental thing we're saying over and over and over and over again???
A/B(C+D) IS NOT EQUAL TO A/B*(C+D) In your example, using the exact equation you gave: Equation: A/B(C+D) Substitution: 10/20(30+40) Simplification: 10/20(70), and since parenthesis are solved first, it's 10/140 Solve: 1/14 = .071
__________________
Arcana Recordings 
April 8th, 2011, 02:41 AM  #31 (permalink)  
Senhor Testiculo
Join Date: Sep 2004
Location: California
Posts: 11,832

Quote:
It's still 2(12), it's two quantities of whatever is inside the parentheses, so you still solve those before moving onto division.
__________________
Arcana Recordings 

April 8th, 2011, 02:44 AM  #32 (permalink)  
Den Mørke Natt
Join Date: Oct 2008
Location: Sacramento, CA
Posts: 3,044

Quote:
Like I have said many times so far you HAVE to simply expressions, this was something you should have learned very well in any basic algebra class around the same time you learned PEMDAS. Simplifying expressions always comes before you can do anything else. The P in PEMDAS means that you have to simply what is in the parenthesis, simplify means, get rid of the parenthesis entirely before you continue on and in our given equation the step to get rid of the parenthesis looks something like this: = 48/2(9+3) = 48/2(12) = 48/24 = 2 exactly, you can use a quantity of an expression to divide another number because that would mean you would go from having 2 quantities of 9+3 to 12 quantities of 9+3
__________________
Corvus Audio For custom electronics, mods and repair, email: CorvusEngineering@gmail.com My band's Facebook Download our EP 

April 8th, 2011, 02:44 AM  #33 (permalink) 
Senior Member
Join Date: Jun 2008
Posts: 616

But were dealing with order of operations here....
Rule 1: First perform any calculations inside parentheses. Rule 2: Next perform all multiplications and divisions, working from left to right. Rule 3: Lastly, perform all additions and subtractions, working from left to right. 
April 8th, 2011, 02:46 AM  #34 (permalink) 
Senhor Testiculo
Join Date: Sep 2004
Location: California
Posts: 11,832

Once again, missing the point entirely.
Do we seriously have to FOIL this out? It's basic distributive property. 2(9+3) can also be written as ((2*9)+(2*3)) if you go back to 9th grade and distribute the 2 out to the numbers it's bound to by parentheses.
__________________
Arcana Recordings 
April 8th, 2011, 02:49 AM  #35 (permalink) 
MAX LOUD PRESETS¯\(°_o)/¯
Join Date: Apr 2008
Location: Sydney, Australia
Posts: 3,675

I'm surprised. Most other sources for this have a pretty even 50/50 split between 2 and 288. When I first saw it I thought 'of course its 2, anyone thinking 288 is a retard', but when I saw an explanation, 288 is the most logical answer.
I'm sorry, what? I haven't done maths in a while, but I did top level maths in highschool, which AFAIK is about equal to first or second year uni level maths in the US, just for reference. Not that this matters because this is 8th grade stuff, and not ONCE have I ever heard this statement uttered. A(B+C) = A*(B+C). They are EXACTLY the same. I dunno where you've picked this up. Usually it doesn't matter, but here it does. = 48/2(9+3) = 48 ÷ 2 * (9+3) [ this statement is exactly the same as the one above / = ÷; A(B+C) = A*(B+C). ] = 24 * 12 = 288 I think we need JBroll up in here. edit: my internet is being retarded so I'm like 4 posts late, argument still stands though. Give me a refernce for A(B+C) = A*(B+C) because I have never in my life heard that. 
April 8th, 2011, 02:55 AM  #36 (permalink) 
Senhor Testiculo
Join Date: Sep 2004
Location: California
Posts: 11,832

A(B+C) is "A quantities of the sum of B and C," not "A times the sum of B and C."
A is latched to (B+C) and has to be solved as ((A*B)+(A*C)). We can simplify (B+C) so we don't have to distribute the 2, but it still stands that it's 2(something), and not 2 as a separate integer times (something). *edit* I realize it sounds retarded to say that "two of x is not equal to two times x," because in that isolated instance they are most definitely equal. The problem is that "two of x" reacts completely different than "2 times x" when paired with equations like in the OP.
__________________
Arcana Recordings 
April 8th, 2011, 02:56 AM  #37 (permalink) 
Den Mørke Natt
Join Date: Oct 2008
Location: Sacramento, CA
Posts: 3,044

Now that I think about it 48/2*(9+3) would still be two because the correct notation would still be
48  = 2 2*12 if you wanted the correct notation to give you 288, it would have to be written 48  (9+3) = 288 2 This is why computer notation SUCKS!!!
__________________
Corvus Audio For custom electronics, mods and repair, email: CorvusEngineering@gmail.com My band's Facebook Download our EP 
April 8th, 2011, 03:01 AM  #38 (permalink) 
Senhor Testiculo
Join Date: Sep 2004
Location: California
Posts: 11,832

Despite being from NorCal, the snowy man is correct.
The problem is that in computerspeak it's ambiguous  it's unclear if whoever wrote the equation means for it to be (48/2)(9+3) or if they want it to be (48)/(2(9+3)). That said, it's still completely wrong to interpret 2(9+3) as 2*(9+3).
__________________
Arcana Recordings 
April 8th, 2011, 03:03 AM  #39 (permalink)  
MAX LOUD PRESETS¯\(°_o)/¯
Join Date: Apr 2008
Location: Sydney, Australia
Posts: 3,675

Quote:
2x and 2*x are the exact same thing, right? Or are even those 'paired'? I need a source on this, because it's just not right. Lets make it 48/2(x), where x=9+3. Same equation. = 48 / 2 (x) = 48 ÷ 2 * x = 24 * x = 24 * (9+3) = 288. Unless you can provide some proof that a / sign means that absolutely everything in the entire equation following that sign is now a denominator, or that 2x != 2*x, or at least 2*x is not 'as important' as 2x, then I don't know what to say. 

April 8th, 2011, 03:04 AM  #41 (permalink) 
Senior Member
Join Date: Jun 2008
Posts: 616

I know that we foil but in this case we dont have and extra parenthesis to tell us that 2 is "latched" to 12
48/2(9+3) How can we assume that this problem is 48/(2(9+3)) ???? Thats what I dont get about your explanation man, Ive had many of these types of problems and I have always worked through them using the order of operations method and managed to get it right. To be fair ive taken a couple of math classes so far up to Calculus II. 
April 8th, 2011, 03:12 AM  #42 (permalink)  
Senhor Testiculo
Join Date: Sep 2004
Location: California
Posts: 11,832

Quote:
I know that 2 is 'latched' to (9+3) because it's written as 2(9+3) and not 2*(9+3). In your example, you need to solve for X first, because it's 2 quantities of x, not just 2 times x. The isolated product is the same, but you need to do it first to simplify the equation. Deryk, I know FOIL is for two separate binomials... don't really give a fuck in this case, it's the same logic. mortum, we can't assume the problem is written as anything really, because it wasn't written  it was typed. That's why we're running into issues. If this person wrote it out in standard notation, it'd be obvious as to which term was a denominator and which was supposed to be dealt with after the division. In this case, since it's written as 2(9+3), as per my explanations above, we have to assume that it's (48)/(2(9+3)). In the math classes you'd have taken, the professor (hopefully) wouldn't be dumb enough to be as ambiguous as the author of this equation.
__________________
Arcana Recordings Last edited by JeffTD : April 8th, 2011 at 03:14 AM. 

April 8th, 2011, 03:17 AM  #44 (permalink)  
Senior Member
Join Date: Jun 2008
Posts: 616

Quote:
Ah i see your point now, this is something that is hard to catch on though. 

April 8th, 2011, 04:27 AM  #47 (permalink) 
Senior Member
Join Date: May 2005
Location: Milton Keynes, UK
Posts: 3,800

2
__________________
Ed Sokolowski Follow me on facebook: EAS STUDIOS Follow me on twitter  http://twitter.com/easstudios Drum Quantizing + Reamping available + Production + Mixing  PM me for details 
April 8th, 2011, 04:29 AM  #48 (permalink) 
Anssi Tenhunen
Join Date: Jan 2008
Location: Virrat/Helsinki, Finland
Posts: 9,395

__________________
Check out my youtube channel for audio production tutorials http://www.youtube.com/ahjteam http://soundcloud.com/ahjteam/sets/debutalbum 
April 8th, 2011, 05:23 AM  #50 (permalink) 
Senior Member
Join Date: Jul 2005
Location: Germany
Posts: 2,032

288 imho, but the equation is unclear as fuck.
the way i see it, 48/(2(9+3)) = 2, and 48/2(9+3) = 288. if there's no parenthesis, there is none. i just don't understand why many of you guys interpret it that way. and 2(9+3) is the EXACT same thing as 2*(9+3). AB = A*B. also, major +1 to this one: "In the math classes you'd have taken, the professor (hopefully) wouldn't be dumb enough to be as ambiguous as the author of this equation." 
Thread Tools  

