College kid asks university ring theorist about 48 ÷ 2(9+3)

[slippa]

Deal with parenthesis first.

The question is fawking stupid though. If this kinda thing ever came up in an actual equation/proof then either;

The person who wrote it like that is an idiot or, more likely,

It's obvious what to do from the context.

Yes deal with them first, but do they need to be eliminated from 2(12)? Technically it changes to 2x12 but its still written with parentheses so shouldnt we work that first?

Missed the thread about this, dont know if this has been covered.

[HockeyJon]

The answer was that the question is poorly written and no sensible professor would write a question that way and for arguments sake if he did slip up and write a poorly written question like that he would accept both answers.

That's basically what I was thinking as well. Two answers could be ascertained depending on how you interpret it. It was a stupid way to write that in my view.

[UjustGotTrolled]

2 crew checkin in

[TryHarderFish]

didn't even know about pemdas

probably just a bum off the street.

or maybe since he's really old he hasnt been in elementary school since the 1940s. when was that pemdas **** even invented?

[feardafronfz3]

[kiwimac]

ring theory is like the highest math there is, it's still being created if i'm not mistaken

I did some ring theory in my maths degree, it's not that difficult (at least the basics aren't). A ring is just a set endowed with an addition and multiplication operation, and satisfying certain other properties. The easiest way to think of it is as a generalization of a set like the integers.

nothing about math is a toss-up, which is why math is so powerful: math is absolutely absolute for ALL instances, there is never a toss-up. In equations you do addition and multiplication before any division and subtraction because multiplication and addition are commutative.

Division is multiplication. For example, division on the reals is defined as follows: for any a,b,c in R

a/b=c iff a=bc and b is not 0

You argument makes no sense.

You are so phucking dumb holy sh*t.

MULTIPLICATION DOES NOT TAKEN PRECEDENCE OVER DIVISION

WHY DO YOU THINK ITS PEMDAS FOR SOME, AND BEDMAS FOR OTHERS? M/D ARE DONE FROM LEFT TO RIGHT, NO PRECEDENCE.

the different tiers of order of operations
terms inside brackets
exponents and roots
multiplication and division
addition and subtraction

Actually, the left to right rule is something that seems to be taught a lot at school, but is not really a convention that is used by mathematicians. Grouping by parentheses should always be used to avoid ambiguity.

[MortimerC]

wow @ people still arguing.

[IllPhill]

Berkeley brah checking in. Evans hall, ugliest building on campus ftw

[Deezenutz]

In mathematics, ring theory is the study of rings—algebraic structures in which addition and multiplication are defined and have similar properties to those familiar from the integers. Ring theory studies the structure of rings, their representations, or, in different language, modules, special classes of rings (group rings, division rings, universal enveloping algebras), as well as an array of properties that proved to be of interest both within the theory itself and for its applications, such as homological properties and polynomial identities.
Commutative rings are much better understood than noncommutative ones. Due to its intimate connections with algebraic geometry and algebraic number theory, which provide many natural examples of commutative rings, their theory, which is considered to be part of commutative algebra and field theory rather than of general ring theory, is quite different in flavour from the theory of their noncommutative counterparts. A fairly recent trend, started in the 1980s with the development of noncommutative geometry and with the discovery of quantum groups, attempts to turn the situation around and build the theory of certain classes of noncommutative rings in a geometric fashion as if they were rings of functions on (non-existent) 'noncommutative spaces'.
Please refer to the glossary of ring theory for the definitions of terms used throughout ring theory.

The fuk?

[NYRFan68]

http://math.berkeley.edu/~jawolf/vitae.html
The guy certainly is no slouch.

[my.self]

http://math.berkeley.edu/~jawolf/vitae.html
The guy certainly is no slouch.

woah, masters 1 year after bachelors and phd 3 years after bachelors? hes either super smart or schooling did not take that long back then.

[SuupaBuu]

Not this **** again.

There's absolutely no reason you should get 2 if you do the question as is, unless you separate 48 and 2(9+3) as the numerator and denominator separately ONLY by converting the / sign as a fraction line.

[Resonator]

The answer is 2, idk why this is so difficult.

a. 48/2 (9+3) (parens are ALWAYS first)
b. 48 / 2(12) (commutative on the denominator)
c. 48 / 24 (reduce)
d. 2 / 1
e. 2




There is no other possible answer. Even when you do left-to-right mult/add comes before division/sub. wtf is the big deal? (yes, CS degree. come at me algo bros)

lol, you can't just forget about that division sign when distributing the 2.

What you're essentially saying is that you can do this:

48
---(9 + 3)
2

=

48(18 + 6)

What kind of distribution is that?

[kiddink]

I don't know why miscers argue over this stuff.

To real mathematicians this is comparable to 9 years old going up to you and saying, "THIS IDIOT THINKS 2 x 3 is 6 BUT I THINK IT'S 5"

[bobbylemke]

The problem can't be solved... there's no equal sign.

[Gzus]

Camera guy is annoying as hell

[SICKK]

Berkeley brah checking in. Evans hall, ugliest building on campus ftw

I spent a lot of time there, it sucked azz.

[iliftpesos]

ring theory is like the highest math there is, it's still being created if i'm not mistaken

guaranteed 'F' unless youre a wizard (srs)

[etali]

In the UK we don't get taught the order as PEMDAS, we call it BODMAS - at least my really old-fashioned math teacher did. The idea is the same, and we were told that divide/multiply are interchangeable - just do whichever appears first.

Then again, I had to spend ages getting out of the habit of calling everything a 'bracket', so maybe my teacher just sucked.

[jason92]

this guy looks like he straight up sits at home and draws up math problems all day and solves them out

[MortimerC]

I don't know why miscers argue over this stuff.

To real mathematicians this is comparable to 9 years old going up to you and saying, "THIS IDIOT SINCE 2 x 3 is 6 BUT I THINK IT'S 5"

Pretty much this. People can't let go

[Ohknats]

[Famin3]

Google says this:

(48 / 2) * (9 + 3) = 288

http://www.google.com.au/search?hl=e...&aqi=&aql=&oq=


Is google ever wrong?


Edit: I know it changes the syntax, but that is how the equation is expressed using general convention