48÷2(9+3) = ????

[KALSTER]

thats what you're taught in school.

That might be your problem here. I also remember things more or less as you do, but who is to say that what we are taught at that level is particularly rigorous? As an example, look at Newton's laws of motion as they are taught to us in school. We now know that they are not accurate at relativistic speeds, yet are taught as fact (they are accurate enough at non-relativistic speeds for our purposes though). But that just shows you that we can't be taught everything in school. Look at complex numbers and how that opposes what we were taught in school.

[rustypup]

primary/high school education is made up of lots of simple lies which are there to teach us how to study, process and retain information. this is hardly surprising. unless we expect a child in grade 5 to grasp complex exponentials...

the black box approach is the fastest route, as long as care is taken to expunge this nonsense in the tertiary environment, (and i've met a number of tertiary educators who bemoan the struggle they experience in correcting the black-box fallacies along with the interruptions they cause)

getting upset over the fact that "they lied to me!" is a little strange... this is obvious to most school leavers... nobody is responsible for our education except ourselves. we can choose to cleave ourselves to ignorance and righteous indignation or we can discover for ourselves what truth may be...

the choice is a personal one. frankly, i have trouble dredging up respect for anyone who insists on wallowing in wilful ignorance....

[RiaX]

no, i dont remember being taught any lies in school rusty ? please leave an example of something taught in school thats not correct? otherwise you just talking nonsense

furthermore you can trust someone who has done maths 3 more than someone who has done maths 1 however this is a simple equation therefore high level qualifications are irrelevant, if the degree of difficulty for equation was much higher then a qualified mathematician would hold more weight, in otherwords i dont need a mathematician to answer 1+1

also whats with the i infront of everything ?

and @ ron why lock a topic in the middle of debate ? we must use logic and deduction to come to a conclusion

[PureFire]

Its just an attempt to say, i dont know what im taking about, so im going to say that everything taught in school is lies.

If thats the case, then there should be no maths in the schooling system or everyone should learn university maths in high school.

i maintain however that BODMAS rules stay in place, whether you're a grd7 pupil, or a 3rd year university student.
you cannot change the rules to suit you just because you're unhappy accepting that you're wrong!

2(9+3) is equal to 2x9 + 2x3, or 2y if (9+3) = y.

if you solve 48÷2y, you arent going to say 48÷2xy. (multiply by y)
You're going to simplify it first, and then substitute back for y.

48÷2y =
24÷y=
24÷12= (y = 9+3) - Substitution

Then you end result is still 2.

if you dont, im sorry, but then i dont know how you got your 3rd year maths qualifications unless you bought them.
This ISNT difficult.

there are "many ways" to solve this yes, but you either do BODMAS and multiply into the brackets first, or you do substitution and simplification.
those are the only "many ways" to solve this.

[rustypup]

lie-to-children

genuine misconceptions are resistant to further instruction, and are often believed firmly (sometimes passionately) by adults

the earth is not like a magnet... the planet's magnetic field is far more complex...
atoms aren't little perfect spheres with orbiting moons of electrons...
rainbows have virtually nothing to do with the mechanics of prisms...

there are thousands of these... and they're all necessary... because taking the time to provide the truth would eat into the time required for other subjects...

this is a simple equation therefore high level qualifications are irrelevant

i disagree... when you're using a toy spanner to assemble an engine, you're doing it wrong...

[WiK1d]

Oh bloody hell, just give it up.

(9+3) is not flipping y.

[PureFire]

and 48÷2(9+3) does not equal 288 unless you're completely daft and bought your qualifications!

[hamin_aus]

and 48÷2(9+3) does not equal 288 unless you're completely daft and bought your qualifications!

u mad?

[Prime]

no, i dont remember being taught any lies in school rusty ? please leave an example of something taught in school thats not correct? otherwise you just talking nonsense

Physics for one thing - g is not equal to 10.

The thermodynamics you do in high school for another. PV = nRT is generally not true.

[hamin_aus]

no, i dont remember being taught any lies in school rusty ? please leave an example of something taught in school thats not correct? otherwise you just talking nonsense

Physics for one thing - g is not equal to 10.

The thermodynamics you do in high school for another. PV = nRT is generally not true.

Centrifugal force....

[Tribble]

and 48÷2(9+3) does not equal 288 unless you're completely daft and bought your qualifications!

So you think I am daft do you? Just because I see no absolute truth in your logic? Because you are unable to accept that there may be two answers instead of one?

[RiaX]

no, i dont remember being taught any lies in school rusty ? please leave an example of something taught in school thats not correct? otherwise you just talking nonsense

Physics for one thing - g is not equal to 10.

The thermodynamics you do in high school for another. PV = nRT is generally not true.

g = 10 is a rounded up figure to make equations easier for children at that level its still not a lie, the force of gravity doesnt equal exactly 9.8m/s either

pV = nRT is correct but never used because its a theoretical equation for what is known as an ideal gas which doesnt exist its function is to explore the theory behind the physics of gas molecules, again its not incorrect without it you wouldnt have the more complex real gas equation as all real gas models are derived from an ideal gas. If you were to see the real gas equation you will cry

There is a difference between simplified and plain wrong

@rusty nothing in school is simplified to the extent of being wrong like "the earth is a magnet", again you missed the point perhaps you should get a refund from your school, the point of using a prism is to demonstrate the effects of refraction which occurs thus creating the rainbow.

anyways back to topic and mathematics:

@ wik1d

explain to me why he cant do this:

let (9+3) = x ? he is simply assigning a value to an algebraic term, which is allowed in mathematics

again make it into a graph to understand:

f(x) = 48 ÷ 2x ... you get a hyperbola

however

f(x) = 24x ... you get a straight line with a gradient of 24

just goes to show how important writing proper mathematics can be, sometimes even more important than the actual process of solving the equation

[PureFire]

Thank you RiaX...
Someone who understands!

[Bladerunner]

i dont need a mathematician to answer 1+1

I am not posting in this thread to debate this specific problem anymore, I've made my point that it's ambiguous. I'm not budging and the rest clearly aren't either.

I just wanted to ask if you could perhaps prove to me that 1+1=2 ?

[RiaX]

i dont need a mathematician to answer 1+1

I am not posting in this thread to debate this specific problem anymore, I've made my point that it's ambiguous. I'm not budging and the rest clearly aren't either.

I just wanted to ask if you could perhaps prove to me that 1+1=2 ?

lol to be honest i wouldnt know how to prove that, maybe if i use some apples i dont know? thats a very good question how would you prove that?

[jee]

The writer of the software could have been wrong.

Yeah, that's usually the problem.
.

That poses a serious problem then - you cannot believe your calculator unless you know the programmer has not made a mistake.

[Bladerunner]

i dont need a mathematician to answer 1+1

I am not posting in this thread to debate this specific problem anymore, I've made my point that it's ambiguous. I'm not budging and the rest clearly aren't either.

I just wanted to ask if you could perhaps prove to me that 1+1=2 ?

lol to be honest i wouldnt know how to prove that, maybe if i use some apples i dont know? thats a very good question how would you prove that?

No you can't use apples. Then you're giving an example not a proof.

The exact proof I don't know, but I know the principle behind it. You must build the number system, for example by defining 0 and 1. Then from 0,1 you create 2. From 0,1,2 you create 3, etc.

You might have to prove before you start that successors do exist.

My point was that you do indeed need a mathematician to tell you that 1+1=2. I believe that's covered in real analysis. It just goes to show that not everything can be taken for granted. Was a bit of a bother when I did ring theory. You first need to show always that addition exists, multiplication exists, 0 exists, 1 exists... you couldn't assume it was a ring. Of course the first test was a disaster. We had no idea how our lecturer would pose the questions, he was an old-school lecturer. He would walk in, look at us briefly and smile. Then start doing some proofs or theory. If there were no questions, he was done. (Normally there weren't because he got angry if someone would ask a stupid/simple question, which led to everyone being too afraid to ask questions.) Anyway, us not having any past papers to go on thought the test was so easy; we assumed so many things that there were big red zeroes all around everywhere on our test papers Nevertheless it was still the coolest subject I've ever taken.

[RiaX]

lol, my analitical chemistry lecturer was like that :/ harsh

but who said an example cannot be used as proof ? If i take an object and drop it illustrates the force of gravity

[Tribble]

But does it prove gravity

[RiaX]

yes it does it shows that the object i dropped is attracted to the earth , it doesnt mathematically define gravity though

[Bladerunner]

I'm not going to explain it in detail. Something can be disproven with an example. To prove something you need to prove it holds for every possible value. It's covered in discrete math, read up on it.

[RiaX]

naa you got a commie avatar so its all lies !

jj

[Tribble]

yes it does it shows that the object i dropped is attracted to the earth , it doesnt mathematically define gravity though

Drop a helium filled balloon and prove gravity

[jee]

how about revisitng the Monty Hall problem?

[Prime]

yes it does it shows that the object i dropped is attracted to the earth , it doesnt mathematically define gravity though

No, it tells you something fell to the earth.

You haven't proved what caused it.