By using this site, you agree to our Privacy Policy and our Terms of Use. Close

Forums - General Discussion - Mathematical dispute

The answer is 2 and always will be 2.



           

Around the Network
Vertigo-X said:
IIIIITHE1IIIII said:
I think they should have written: 48/(2(3+9)) if they wanted to make sure that the answer is 2.

Still, I'm not too certain if the number 2 is part of the brackets or not. And different mathematicians come up with different answers so I really don't see the discussion value.

In school I was taught that there may be two different ways of solving this, by the way.


On your first part, that is right. If you solve the parenthesis portion first, the resulting number becomes ordinary; there is no special rule that applies to it. Simply having the two next to it doesn't mean it's automatically distributed; the distributive property is a way of simplifying  and not an actual order of operation.

 

Like you said, if people want to get two for an answer, they'd need to place brackets around the two and the parenthesis. Think of it this way: how would you put this into a calculator? You'd put additional brackets around the 2(3+9) if you wanted the answer to be two. :)


Truthfuly i don't use calculators unless i really need it for  calculations like getting the root values of non solvable roots or powering fractions. the reason being that different calculatos are programmed differently (as in this case, checked my Polish calculator, it gave me a 2, checked my firends calculator form england and gave me 288).

Maybe the difference comes from how notations are treated in different parts of the world?



If i lose access to this profile as well....I'm done with this site.....You've been warned!!.....whoever you are...

Happy Wii60 user. Me and my family are a perfect example of where hardcore meets casual and together mutate into something awesome.

Personally I have been taught the BODMAS rule from childhood. So basically you solve anything inside the bracket, orders of magnitude, division, multiplication, addition and subtraction respectively.

The problem we have is:
48÷2(3+9)

Applying the above rule we first do the operation inside the bracket:
3+9=12

Keeping in mind that the relation between anything inside the bracket with anything outside it is just a multiplication (example: 3(5) is the same as 3*5 which both equal 15), we perform the division in this problem:
48÷2=24

Finally we perform the bracket multiplication:
24(12)=288

So to show everything in order:
48÷2(3+9)
=48÷2(12)
=24(12)
=288

Just as an extra, typing the exact equation as it is given into excel gives 288 as well. Of course that's how excel was programmed anyway.


Essentially this is a simple notation problem and how you approach it. Problems like these are very contextual.



 

I'm not sure why people would still say 2 after everything we've said in this thread :/

There's no doubt in my mind that it is 288.





Around the Network
Boutros said:

Haha ;)

This also reminds me of one of my favourite quotes:

"Remember, there are no stupid answers, just stupid people." ;P



If i lose access to this profile as well....I'm done with this site.....You've been warned!!.....whoever you are...

Happy Wii60 user. Me and my family are a perfect example of where hardcore meets casual and together mutate into something awesome.

Here's an old sort of mathematician joke:

5 cents = (25 cents)^1/2 = (1/4 dollars)^1/2 = 1/2 dollars = 50 cents



IIIIITHE1IIIII said:
I think they should have written: 48/(2(3+9)) if they wanted to make sure that the answer is 2.


Yes exactly, as someone who does physics at university we have to pretty much fill our entire equation with brackets to avoid problems like these. They should have put another bracket infront of the 2 like you did if they wanted the final answer to be 2.

If you use sofware packages like excel, you have to put the brackets in to get 2. In fact I put the exact equation into excel right now and it gives 288. Of course you could argue the programmers made it use the order we are using, but I think this is the norm, at least where I am from anyway.



 

It's two. The answer is two. BODMAS would suggest 288, but it's 2.



 

Here lies the dearly departed Nintendomination Thread.

yanamaster said:
Boutros said:
yanamaster said:
Boutros said:
yanamaster said:
Well, i stand by the answer 2. If the original equation was 48/2*(3+9) then sure, the answer would 288, but when we have a parenthesis that looks like 2(3+9), then the 2 is part of the parenthesis and has to be calculated with what lies inside the brackets.

2(3+9) = 2*(3+9)

It's the exact same. And in both case 2 isn't part of the parenthesis.


Ah, yes, of course that there is a multiplication sign in both situations, but tell me this then, how would you solve this then:

6x²+x / x*(4x+2x+1)

6x²+x / x(4x +2x +1)

?

6x² + 1/(4x+2x+1)

6x² + 1/(4x+2x+1)

lol

Well the answer is 1 for me.

6x² + x/x(6x+1) = 6x² + x/6x² + x = 1

We will have to agree to disagree but honestly, the first equation that i gave you, i would have solved it just like you, but the second one indicates that the x before the parenthesis is part of the parenthesis and should not be dealt with until you solve everything inside and beside the parenthesis. 


What.

 

How is the answer one? By your own method the expressions (i.e. this isn't an equation; it would have to equal something, like zero from the start, to be one) work out as follows:

6x²+x / x*(4x+2x+1)

6(x^2) + x / [x * (4x + 2x + 1)] = 6(x^2) + x / [6 * (x^2) + x] = 6(x^2) + 1 / (6x + 1)

Unless it equals one from the start, this expression has no definitive answer.

 

This is how I'd simplify it:

6(x^2) + x / x * (4x + 2x + 1) = 6(x^2) + (1 / 1) * (6x + 1) = 6(x^2) + 6x + 1

 

I mean, just how would you guys solve this one:

7x / 14(x^2) / 7x

Would you go straight left to right, or would you pretend that 7x to the far right is back in the numerator again?



The BuShA owns all!