48/2(9+3) = ???
- Thread starter Morgan C
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TheWinterSnow
Den Mørke Natt
LOL it is so great to be right when almost everyone else is wrong
It is in that / sign... where the fuck does the sign say that it extends over the (9+3) ???
because the slash means divide which is the same as placing the number over the fraction, and because the 2 is multiplied by the sum in the parenthesis that product has to be taken into account before you can continue to the next step.
JeffTD
Senhor Testiculo
I'm not; I actually have social skills, but my roommates are computer science/biomed engineers and the three of them concur - but enough with the dick measuring.
Like Wolfe said, you guys are stuck in computer land. 2(9+3) DOES NOT EQUAL 2*(9+3) in this case, because it throws off the order of operations.
Using your example, what do you think 200/10(5) would be equal to?
TheWinterSnow
Den Mørke Natt
Before I start I am an Electrical Engineer...
What you have failed to see is that Google rewrites the equation to 48/2*(9+3) which is not the same as 48/2(9+3). The problem that google has not dealt with the fact that there is a difference between directly coupling numbers to expressions and dividing them with an asterisk and just converts 2(9+3) to 2*(9+3) in which yes the answer would be 288.
The fatal flaw that is not being recognized is that all "expressions" MUST BE SIMPLIFIED!!!
The P in PEMDAS means parenthesis, and means that you not only do the equation in the parenthesis but you must also simplify the equation so that there are no parenthesis left.
Mutant
I hate that supercow !
Quote me any serious book that adds one more rule to the standard.
Parentheses
Exponents
DM Division and Multiplication
AS Addition and Subtraction
Should it be
Parentheses
Exponents
MD Multiplication and Division (but Multiplication first if there is no * sign)
AS Addition and Subtraction
???
AB means and will always mean just one thing: A*B
Parentheses
Exponents
DM Division and Multiplication
AS Addition and Subtraction
Should it be
Parentheses
Exponents
MD Multiplication and Division (but Multiplication first if there is no * sign)
AS Addition and Subtraction
???
AB means and will always mean just one thing: A*B
motomoto
Member
- Mar 20, 2009
- 950
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- 16
LOL this is great
The 86 is clearly smarter than the 85 !
Haaaaaaaaahahahaha
My 83 is clearly smarter than your 85 too
JeffTD
Senhor Testiculo
AB means A*B, but A(B) means (A*B).
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).
Mutant
I hate that supercow !
And what happens if you simplify by removing the parenthesis without adding the * sign ???
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.
xmortumx
Member
- Jun 17, 2008
- 615
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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.
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.
JeffTD
Senhor Testiculo
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
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
JeffTD
Senhor Testiculo
No no no no no no no.
It's still 2(12), it's two quantities of whatever is inside the parentheses, so you still solve those before moving onto division.
TheWinterSnow
Den Mørke Natt
There is another rule that is not connected to PEMDAS but does effect it, they mention both rules in high school but for whatever reason never tell you that they are interconnected. That only happens in high school when they are cramming calculus down your throat.
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
xmortumx
Member
- Jun 17, 2008
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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.
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.
JeffTD
Senhor Testiculo
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.
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.
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.
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.
JeffTD
Senhor Testiculo
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.
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.
TheWinterSnow
Den Mørke Natt
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!!!
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!!!
JeffTD
Senhor Testiculo
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).
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).
Ok what if we split it up.
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.
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