Facebook Math Debate: 6÷2(1+2)=?

[ThunderAeroI]

Well, I said 1. Mainly because I took 2(1+2) to be the denominator of the fraction 6 / 2(1+2)

so thats 6/6 or 1/1 or just 1

it is cleaner that way. AS others have pointed out, should you really want the answer to be 9, you should use different syntax. (6/2) * (1+2) = (3) * (3) = 9.

As its written 1 is the correct answer....lalalalalalalal I don't hear you....

 

[Lindley]

isn't E= Mx(CxC), it's (MxC)x(MxC), yes?

Actually, now that I'm thinking about it, these equations are saying the exact same thing. The only difference is that in the second version you've used the distributive property to re-write the problem.

Afraid not. There's only one factor of M.

 

[RoJoHen]

Ooh, good call. I am really not good at reading math on the computer.

 

[Jadzia]

The only difference is that in the second version you've used the distributive property to re-write the problem.

The distributive property applies where you have both addition and multiplication

eg, E = (M+C) × C = (M×C)+ (C×C)

 

[Australis]

isn't E= Mx(CxC), it's (MxC)x(MxC), yes?

Actually, now that I'm thinking about it, these equations are saying the exact same thing. The only difference is that in the second version you've used the distributive property to re-write the problem.

Man I suck at this type of maths.

Let's give values to this

E= 2x3(squared)

So it's either (2x3)x(2x3) = 36
Or 2x(3x3) = 18

Also, no one's reinterpreted the equation, so that C is to the left of the equal sign. Any thoughts?

For me, and it's probably entirely wrong, something like
C = square root of (E-M)

 

[Jadzia]

In PIDMAS, the I is for Indices.

When you write E = MC^2, the ^ symbolises Indices, and you do these before multiplication.

C^2 can be replaced with C×C, giving E = M×(C×C)

Because multiplication is associative, we can omit the parentheses, giving E = M×C×C

If we want to rearrange the equation, divide both sides by M, giving E/M = M×C×C / M

The two M on the right hand side cancel, giving C^2 = E/M

C = √ (E/M)

 

[Australis]

Thank you, Jadzia, that was wonderfully lucid.

 

[JarodRussell]

isn't E= Mx(CxC), it's (MxC)x(MxC), yes?

Actually, now that I'm thinking about it, these equations are saying the exact same thing. The only difference is that in the second version you've used the distributive property to re-write the problem.

Man I suck at this type of maths.

Let's give values to this

E= 2x3(squared)

So it's either (2x3)x(2x3) = 36
Or 2x(3x3) = 18

Also, no one's reinterpreted the equation, so that C is to the left of the equal sign. Any thoughts?

For me, and it's probably entirely wrong, something like
C = square root of (E-M)

Wow, dude, basic math. That's elementary stuff. Kids learn that in, I dunno, the cradle.

 

[DarthTom]

If you place the equation into an excel table and replace the standard division sign with a ' / ' the correct answer 9 comes up in less than 5 seconds where is the debate? Even without using Excel I don't know how anyone else derives another answer.

 

[iguana_tonante]

"Excel: Better Than Your Brain."

I weep for humanity.

 

[Naira]

The programmer in me knows that 6a/2a is probably an incorrect attempt to write 6*a/(2*a) [...].

This.

I first saw the whole debate about this expression here and upon seeing the poll (and not reading the first poll) my thoughts were "Well... 9 but I guess you meant 1".

 

[Australis]

Actually, now that I'm thinking about it, these equations are saying the exact same thing. The only difference is that in the second version you've used the distributive property to re-write the problem.

Man I suck at this type of maths.

Let's give values to this

E= 2x3(squared)

So it's either (2x3)x(2x3) = 36
Or 2x(3x3) = 18

Also, no one's reinterpreted the equation, so that C is to the left of the equal sign. Any thoughts?

For me, and it's probably entirely wrong, something like
C = square root of (E-M)

Wow, dude, basic math. That's elementary stuff. Kids learn that in, I dunno, the cradle.

Meh. Maths was never, ever my thing.

 

[SilentP]

Gee, I answered '1' as well, and I took A level Maths only 4/5 years ago

Somewhere along the line, I must have somehow got it into my head to resolve numbers that aren't separated by the actual 'x' multiplication or '÷' division symbol first (as in this example the '2(1+2)') and then resolve everything else.

I remember the phrase BODMAS from somewhere, but it's meaning obviously left me a while ago

If I was writing that problem with the intention of '1' being the answer, I would have written it as 6÷2x(1+2) or (6÷2)x(1+2) for clarity.

 

[DBR]

I got 13.