Math Problem taking the Internet by storm

[tagutcow]

Originally Posted by *#..

How I see this problem is you can redistribute the 2 back into the parentheses. Hence, you'll get:

48÷2(9+3)
48÷(18+6)
48÷(24)
2

There's this property called the "distributive property" that a lot of those people on the physics forum forgot which is just

Remember back in algebra, you could factor out a 2 in an equation like:
(2x+2)
2(x+1)

Same concept, you just have a number (18) instead of a variable (x).

The way it's written is not sloppy at all - most people have just forgotten the basic properties of elementary algebra. Why someone would factor out a 2 from (18+6) is beyond me, but you can do it.

This is called, "assuming your conclusion".

Look, we have a mathematical expression, 48÷2, and the term (9+3) is to be multiplied either by the whole expression, or by just the denominator. If 48÷2 were in parentheses, there would be no confusion. The fact that 48÷2 isn't in parentheses, and the fact that (9+3) is in closer proximity to the denominator of the expression than the numerator, leads me to the conclusion that (9+3) should be multiplied by the denominator. But it is an ambiguous expression that can be interpeted two ways, for reasons that have hammered into the ground.

The expression:

(9+3)48÷2

could similarly be interpeted two different ways, only those two ways would yield the same result, since a(b/c) = (ab)/c, so nobody bothers their pretty little heads over it, and thus it never takes the internet by storm!

 

[CunningSmeagol]

Having read this I feel nothing but contempt.

 

[Dakota rube]

Tagutcow: You didn't have to get all snippy about it!

 

[tagutcow]

Originally Posted by Dakota rube

Tagutcow: You didn't have to get all snippy about it!

I'm trying to fill a Tokyo Slim-shaped hole on this forum.

 

[Dakota rube]

Originally Posted by tagutcow

I'm trying to fill a Tokyo Slim-shaped hole on this forum.
Ah. Then by all means, carry on.

 

[Ajaxv2]

Split the difference; 145.

 

[binge]

Originally Posted by tagutcow

I'm trying to fill a Tokyo Slim-shaped hole on this forum.

That's the grossest thing I've ever read.

 

[intent]

The only thing I learned from this thread is that Canadians call it BEDMAS while Americans call it PEMDAS.

 

[Huntsman]

This problem thing is annoying.

Originally Posted by binge

That's the grossest thing I've ever read.
It's the least-possible thing I've ever read on this forum.

 

[vaalbara]

Originally Posted by *#..

How I see this problem is you can redistribute the 2 back into the parentheses. Hence, you'll get:

48÷2(9+3)
48÷(18+6)
48÷(24)
2

There's this property called the "distributive property" that a lot of those people on the physics forum forgot which is just

Remember back in algebra, you could factor out a 2 in an equation like:
(2x+2)
2(x+1)

Same concept, you just have a number (18) instead of a variable (x).

The way it's written is not sloppy at all - most people have just forgotten the basic properties of elementary algebra. Why someone would factor out a 2 from (18+6) is beyond me, but you can do it.

there's also this nifty thing called the order of operations which necessitates that you take care of what's in the parentheses before anything

the distributive property applies after everything else has already been simplified - which would result in 24*(9+3) = 288

 

[deandbn]

Originally Posted by vaalbara

there's also this nifty thing called the order of operations which necessitates that you take care of what's in the parentheses before anything

the distributive property applies after everything else has already been simplified - which would result in 24*(9+3) = 288

I am sorry but you are incorrect!

The brackets have to be resolved first so it's 2*9 + 2*3 that gives the answer 24, and 48 divided by 24 gives the answer 2.

48 / 2(9+3)
so 48 / (18 + 6)
so 48 / 24
so 2

or

48 / 2(9+3) = 2
so 48 / (18 + 6) = 2
so 48 / 24 = 2

but

48 / 2(9+3) = 288
so 48 / (18+6) = 288
so 48 / 24 = 288
is not correct

 

[Lel]

 

[tagutcow]

 

[vaalbara]

Originally Posted by deandbn

I am sorry but you are incorrect! The brackets have to be resolved first so it's 2*9 + 2*3 that gives the answer 24, and 48 divided by 24 gives the answer 2. 48 / 2(9+3) so 48 / (18 + 6) so 48 / 24 so 2 or 48 / 2(9+3) = 2 so 48 / (18 + 6) = 2 so 48 / 24 = 2 but 48 / 2(9+3) = 288 so 48 / (18+6) = 288 so 48 / 24 = 288 is not correct

http://www.wolframalpha.com/input/?i...289%2B3%29+%3D 48 / 2(9+3) <- stuff inside parentheses gets resolved first 48/2(12) <- if everything is on the same step of PEMDAS, stuff on left gets resolved first 48/2 = 24, 24*12 = 288 get back to me after you're retaken algebra 1

 

[StephenHero]

I vote 2.