Author Topic: 48÷2(9+3) = (Read 42022 times)

Jamesman42 · « **Reply #105 on:** April 17, 2011, 07:30:48 PM »

I would immediately read that as x^(2y) but my logic tells me that it is (x^2)(y)

slycordinator · « **Reply #106 on:** April 17, 2011, 07:35:04 PM »

Quote from: Dimitrius on April 17, 2011, 07:25:44 PM

Quote from: slycordinator on April 17, 2011, 07:18:14 PM
Another example of this is that one could say x^2y = (x^2)*y or x^(2*y).
I'm really intrigued to know how that is anything else but x^(2*y).

The only way it is x^(2*y) is by saying "the parentheses are implied" or by saying "implied multiplication comes before all other operations" but the fact of the matter is that there are no parentheses in the x^2y and it is not a given that implied multiplication comes before the other operations.

Dimitrius · « **Reply #107 on:** April 17, 2011, 07:38:58 PM »

Quote from: slycordinator on April 17, 2011, 07:35:04 PM

Quote from: Dimitrius on April 17, 2011, 07:25:44 PM
Quote from: slycordinator on April 17, 2011, 07:18:14 PM
Another example of this is that one could say x^2y = (x^2)*y or x^(2*y).
I'm really intrigued to know how that is anything else but x^(2*y).
The only way it is x^(2*y) is by saying "the parentheses are implied" or by saying "implied multiplication comes before all other operations" but the fact of the matter is that there are no parentheses in the x^2y and it is not a given that implied multiplication comes before the other operations.

Huh, I see. I would immediately read that as x^(2*y) and not be able to see it any other way.

Jamesman42 · « **Reply #108 on:** April 17, 2011, 07:39:10 PM »

I typed x^2x into my graphing calculator and it graphed x^3, so it seems to be the same deal...read it left to right and with PEMDAS, not what is implied.

ricky · « **Reply #109 on:** April 17, 2011, 07:39:56 PM »

Ok, my only serious post in this thread. This is like a 6th grade problem.

So, here we go, ill make this simple.

48÷2(9+3). PEMDAS = Parenthesis, then exponents, then Multi, then division, addition, subtraction. In that order. and remember, ITS FROM LEFT TO RIGHT.

k. so.

1. Parenthesis = 48÷2(12)
2. No exponents
3. MULTIPLICATION = 48÷24
4. Then division = 2.

YOU GUYS FORGET THE MOST IMPORTANT RULE, ITS FROM LEFT TO RIGHT.

yep.

slycordinator · « **Reply #110 on:** April 17, 2011, 07:47:07 PM »

Quote from: ricky on April 17, 2011, 07:39:56 PM

PEMDAS = Parenthesis, then exponents, then Multi, then division, addition, subtraction. In that order.

Wrong.
PEMDAS = Parenthesis, exponents, multiplication & division, addition & subtraction. Multiplication and division have the same precedence.

15/3*4 is not 15/12 but is 20.

ScioPath · « **Reply #111 on:** April 17, 2011, 07:48:53 PM »

Division is multiplication.

ricky · « **Reply #112 on:** April 17, 2011, 07:50:35 PM »

i spent part of my free time talking about math.

i fail.

slycordinator · « **Reply #113 on:** April 17, 2011, 07:56:01 PM »

You wouldn't be the first person to think that multiplication comes first before division. I was taught that way in third grade but our fourth grade teacher corrected it...

lonestar · « **Reply #114 on:** April 17, 2011, 07:56:09 PM »

Only DTF could argue four pages in six hours about a fucking math problem.

ricky · « **Reply #115 on:** April 17, 2011, 07:56:53 PM »

Quote from: slycordinator on April 17, 2011, 07:56:01 PM

You wouldn't be the first person to think that multiplication comes first before division. I was taught that way in third grade but our fourth grade teacher corrected it...

and im correcting your fourth grade teacher.

ricky · « **Reply #116 on:** April 17, 2011, 07:57:48 PM »

Quote from: lonestar on April 17, 2011, 07:56:09 PM

Only DTF could argue four pages in six hours about a fucking math problem.

well, we spent part of that debating why england (or britain, at this point i dont care) doesn't use the euro.

which doesn't make sense, if youre part of the EU you should use the Euro.

tjanuranus · « **Reply #117 on:** April 17, 2011, 08:07:23 PM »

WTF since when does multiplication come before division? They are on the exact same level of importance. Whichever one is first is what you do. In this case it's division.

ricky · « **Reply #118 on:** April 17, 2011, 08:09:53 PM »

Where in PEMDAS does it mention importance?

parenthesis, exponents, muli, division, add, sub, IN THAT ORDER. FROM LEFT TO RIGHT.

theres nothing in pemdas that says "both mulit and division are of equal importance". thats merely interpretation.

Dimitrius · « **Reply #119 on:** April 17, 2011, 08:12:02 PM »

Quote from: ricky on April 17, 2011, 08:09:53 PM

Where in PEMDAS does it mention importance?

parenthesis, exponents, muli, division, add, sub, IN THAT ORDER. FROM LEFT TO RIGHT.

theres nothing in pemdas that says "both mulit and division are of equal importance". thats merely interpretation.

You do whatever comes first, it's multiplication OR division, add OR substraction. One doesn't come first than the other, one isn't more important than the other.

slycordinator · « **Reply #120 on:** April 17, 2011, 08:12:22 PM »

Quote from: ricky on April 17, 2011, 07:56:53 PM

and im correcting your fourth grade teacher.

Then I guess my math teachers in junior high, high school, and college (where I got a math degree) corrected both my former teacher and you.

As noted above, division *is* multiplication. Dividing by a number is the same as multiplying by the number's inverse.

But in case you don't believe me:
https://en.wikipedia.org/wiki/Order_of_operations
https://www.mathsisfun.com/operation-order-pemdas.html

ricky · « **Reply #121 on:** April 17, 2011, 08:15:48 PM »

Quote from: Dimitrius on April 17, 2011, 08:12:02 PM

Quote from: ricky on April 17, 2011, 08:09:53 PM
Where in PEMDAS does it mention importance?

parenthesis, exponents, muli, division, add, sub, IN THAT ORDER. FROM LEFT TO RIGHT.

theres nothing in pemdas that says "both mulit and division are of equal importance". thats merely interpretation.
You do whatever comes first, it's multiplication OR division, add OR substraction. One doesn't come first than the other, one isn't more important than the other.

THERE IS NO OR. if there was or, it would be PoEoMoDoAoS.

ricky · « **Reply #122 on:** April 17, 2011, 08:16:46 PM »

Quote from: slycordinator on April 17, 2011, 08:12:22 PM

Quote from: ricky on April 17, 2011, 07:56:53 PM
and im correcting your fourth grade teacher.
Then I guess my math teachers in junior high, high school, and college (where I got a math degree) corrected both my former teacher and you.

As noted above, division *is* multiplication. Dividing by a number is the same as multiplying by the number's inverse.

But in case you don't believe me:
https://en.wikipedia.org/wiki/Order_of_operations
https://www.mathsisfun.com/operation-order-pemdas.html

division isn't multiplication.

here's why.

2/2 = 1
2 *2 = 4.

how is that the same?

EDIt = AND WIKIPEDIA ISNT A VALID SOURCE *college professor rant*. I shit on eggs is a perfect example.

bloop · « **Reply #123 on:** April 17, 2011, 08:17:16 PM »

oh boy.

Dimitrius · « **Reply #124 on:** April 17, 2011, 08:18:24 PM »

Quote from: ricky on April 17, 2011, 08:16:46 PM

Quote from: slycordinator on April 17, 2011, 08:12:22 PM
Quote from: ricky on April 17, 2011, 07:56:53 PM
and im correcting your fourth grade teacher.
Then I guess my math teachers in junior high, high school, and college (where I got a math degree) corrected both my former teacher and you.

As noted above, division *is* multiplication. Dividing by a number is the same as multiplying by the number's inverse.

But in case you don't believe me:
https://en.wikipedia.org/wiki/Order_of_operations
https://www.mathsisfun.com/operation-order-pemdas.html

division isn't multiplication.

here's why.

2/2 = 1
2 *2 = 4.

how is that the same?

You apparently don't know what a number's inverse is...

2/2 = 1
2 * (1/2) = 1

slycordinator · « **Reply #125 on:** April 17, 2011, 08:19:23 PM »

He's trolling.

ricky · « **Reply #126 on:** April 17, 2011, 08:20:07 PM »

Quote from: Dimitrius on April 17, 2011, 08:18:24 PM

Quote from: ricky on April 17, 2011, 08:16:46 PM
Quote from: slycordinator on April 17, 2011, 08:12:22 PM
Quote from: ricky on April 17, 2011, 07:56:53 PM
and im correcting your fourth grade teacher.
Then I guess my math teachers in junior high, high school, and college (where I got a math degree) corrected both my former teacher and you.

As noted above, division *is* multiplication. Dividing by a number is the same as multiplying by the number's inverse.

But in case you don't believe me:
https://en.wikipedia.org/wiki/Order_of_operations
https://www.mathsisfun.com/operation-order-pemdas.html

division isn't multiplication.

here's why.

2/2 = 1
2 *2 = 4.

how is that the same?
You apparently don't know what a number's inverse is...

2/2 = 1
2 * (1/2) = 1

I realize that.

but were not talking about inverses.

were talking about multiplication and division.

its one thing to talk about the RELATION of the two, but the reality is THEY ARE SO DIFFERENT THINGS.

blackngold29 · « **Reply #127 on:** April 17, 2011, 08:20:19 PM »

Nobody addressed my point of diving by x is also the same as multiplying by 1/x

Therefore 48 * (1/24) = 2

Also, nowhere in the order of operations can I find "read it left to right." It's what I was taught, but you learn a lot of bullshit in school.

EDIT: ninja'd kind of

Jamesman42 · « **Reply #128 on:** April 17, 2011, 08:20:48 PM »

Quote from: ricky on April 17, 2011, 08:09:53 PM

Where in PEMDAS does it mention importance?

parenthesis, exponents, muli, division, add, sub, IN THAT ORDER. FROM LEFT TO RIGHT.

theres nothing in pemdas that says "both mulit and division are of equal importance". thats merely interpretation.

You are dead wrong. You first do parentheses. Then exponents. Then multiplication/division, which, if there is more than one of those going on, you do it from left to right. Then addition/subtraction (same rule as multi/div.). PEMDAS is merely a mnemonic device to help you remember the order of the tiers, and it is NOT a literal order for ALL of the operations.

If you think I am even slightly wrong I will slap you across our monitors.

Jamesman42 · « **Reply #129 on:** April 17, 2011, 08:22:03 PM »

Quote from: ricky on April 17, 2011, 08:20:07 PM

its one thing to talk about the RELATION of the two, but the reality is THEY ARE SO DIFFERENT THINGS.

Maybe you are not trolling, but division is technically multiplication.

When we divide something by 4, we are actually multiplying that something by (1/4). This may not make sense to you, but it is true.

ricky · « **Reply #130 on:** April 17, 2011, 08:22:14 PM »

Quote from: Jamesman on April 17, 2011, 08:20:48 PM

Quote from: ricky on April 17, 2011, 08:09:53 PM
Where in PEMDAS does it mention importance?

parenthesis, exponents, muli, division, add, sub, IN THAT ORDER. FROM LEFT TO RIGHT.

theres nothing in pemdas that says "both mulit and division are of equal importance". thats merely interpretation.

You are dead wrong. You first do parentheses. Then exponents. Then multiplication/division, which, if there is more than one of those going on, you do it from left to right. Then addition/subtraction (same rule as multi/div.). PEMDAS is merely a mnemonic device to help you remember the order of the tiers, and it is NOT a literal order for ALL of the operations.

If you think I am even slightly wrong I will slap you across our monitors.

yah but the poll says the answer is two.

and everyone in a dream theater forum is smart.

so yah.

Metro · « **Reply #131 on:** April 17, 2011, 08:22:56 PM »

I asked my cousin about this on Facebook. This was his response. Not sure sure this helps or not.

Quote

The order of operations dictates that everything in parentheses is done first, then multiplication/division, then addition/subtraction.

The misleading bit about this equation is that the easy assumption is that, since the 2 is adjacent to the "(9+3)," '2 x 12' should be done next. The reason for this is because we are taught to incorporate the distributive property -- a(b + c) = ab + ac -- without the important caveat that 'a(b + c)' should be viewed as 'a x (b + c)' when it exists in a longer equation such as the one listed above.

The most common answer to the equation in question is 2: 48 ÷ 2(9 + 3) = 48 ÷ (2 x 12) = 48 ÷ 24 = 2
This violates the procedural guidelines of order of operations.

The correct way to solve this equation is this:
48 ÷ 2(9 + 3) = (48 ÷ 2) x (9 + 3) = 24 x (9 + 3) = 24 x 12 = 288

I'm not sure what the debate is here. Putting a number adjacent to a parenthesis is simply shorthand for saying that the first number is to be multiplied by the second. There is not special consideration given to it just because it is written that way.

Hope this helps.

Jamesman42 · « **Reply #132 on:** April 17, 2011, 08:23:43 PM »

^That has been said a bunch of times already.

Jamesman42 · « **Reply #133 on:** April 17, 2011, 08:24:26 PM »

Quote from: ricky on April 17, 2011, 08:22:14 PM

Quote from: Jamesman on April 17, 2011, 08:20:48 PM
Quote from: ricky on April 17, 2011, 08:09:53 PM
Where in PEMDAS does it mention importance?

parenthesis, exponents, muli, division, add, sub, IN THAT ORDER. FROM LEFT TO RIGHT.

theres nothing in pemdas that says "both mulit and division are of equal importance". thats merely interpretation.

You are dead wrong. You first do parentheses. Then exponents. Then multiplication/division, which, if there is more than one of those going on, you do it from left to right. Then addition/subtraction (same rule as multi/div.). PEMDAS is merely a mnemonic device to help you remember the order of the tiers, and it is NOT a literal order for ALL of the operations.

If you think I am even slightly wrong I will slap you across our monitors.

yah but the poll says the answer is two.

and everyone in a dream theater forum is smart.

so yah.

Currently known, there are 24 people who can't do basic math.

ricky · « **Reply #134 on:** April 17, 2011, 08:25:25 PM »

Quote from: Jamesman on April 17, 2011, 08:24:26 PM

Quote from: ricky on April 17, 2011, 08:22:14 PM
Quote from: Jamesman on April 17, 2011, 08:20:48 PM
Quote from: ricky on April 17, 2011, 08:09:53 PM
Where in PEMDAS does it mention importance?

parenthesis, exponents, muli, division, add, sub, IN THAT ORDER. FROM LEFT TO RIGHT.

theres nothing in pemdas that says "both mulit and division are of equal importance". thats merely interpretation.

You are dead wrong. You first do parentheses. Then exponents. Then multiplication/division, which, if there is more than one of those going on, you do it from left to right. Then addition/subtraction (same rule as multi/div.). PEMDAS is merely a mnemonic device to help you remember the order of the tiers, and it is NOT a literal order for ALL of the operations.

If you think I am even slightly wrong I will slap you across our monitors.

yah but the poll says the answer is two.

and everyone in a dream theater forum is smart.

so yah.

Currently known, there are 24 people who can't do basic math.

yah but 24 > 14.

basic math says im right.

Jamesman42 · « **Reply #135 on:** April 17, 2011, 08:26:22 PM »

Trollllllllllllllllllllllllllll

Dimitrius · « **Reply #136 on:** April 17, 2011, 08:27:27 PM »

Quote from: Jamesman on April 17, 2011, 08:26:22 PM

Trollllllllllllllllllllllllllll

His whole existence is that.

blackngold29 · « **Reply #137 on:** April 17, 2011, 08:27:57 PM »

Quote from: Jamesman on April 17, 2011, 08:26:22 PM

Trollllllllllllllllllllllllllll

https://youtu.be/iwGFalTRHDA

Metro · « **Reply #138 on:** April 17, 2011, 08:29:31 PM »

Quote from: Jamesman on April 17, 2011, 08:23:43 PM

^That has been said a bunch of times already.

Eh. I figured it would have.

ricky · « **Reply #139 on:** April 17, 2011, 08:30:05 PM »

no no, i wasn't trolling. but technically, isn't calling someone a troll "trolling"? you can call me a troll, but i haven't resorted to namecalling, all ive done is make legitimate arguments.

the only thing i dont get is when people say multiplication and division are the same thing.

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48÷2(9+3)=

Author Topic: 48÷2(9+3) = (Read 42022 times)