Solve 48

[briangw]

Multiplication takes precedence over division

No, the rule is "multiplication OR division from left to right." I taught Pre-Algebra college classes for the past three years. There isn't any "precedence" rules outside the order of operations.

[briangw]

I spoke with my step father... he says its 2. he says in any problem with the parenthesis.. you have to do the destributive property first. he said you cant just do 48*1/2*12. so he says its 2.. i say its 2... and the guy who posted above me on the calculator says its 2

Technically, either method is right. The catch is how the problem is presented. Instead of saying just "Solve," the instructions need to say solve by order of operations or distributitive property. Open any pre-algebra or algebra text book on the chapters for practice or test at the end and the instructions will say one of the other. If they don't, then you should be able to use this defense in the class you are taking if you solve it one way compared to what the instructor was thinking.

This worksheet has common equations to the one being discussed here:

http://math.about.com/od/algebraworksheets/ss/Algebra-.htm

[anarkhy]

I spoke with my step father... he says its 2. he says in any problem with the parenthesis.. you have to do the destributive property first. he said you cant just do 48*1/2*12. so he says its 2.. i say its 2... and the guy who posted above me on the calculator says its 2

sorry man, i only posted the video to show it can be a dubious problem. actually i am with google who says its 288. Not only google solves the equation it shows the corret writing.

[Astra.Xtreme]

Technically, either method is right. The catch is how the problem is presented. Instead of saying just "Solve," the instructions need to say solve by order of operations or distributitive property. Open any pre-algebra or algebra text book on the chapters for practice or test at the end and the instructions will say one of the other. If they don't, then you should be able to use this defense in the class you are taking if you solve it one way compared to what the instructor was thinking.

This worksheet has common equations to the one being discussed here:

http://math.about.com/od/algebraworksheets/ss/Algebra-.htm

Distributive is multiplication, so you still have to follow order of operations no matter what. That only correct answer is 288.

[briangw]

Distributive is multiplication, so you still have to follow order of operations no matter what. That only correct answer is 288.

If that's the case, then why do those worksheets on my link have a similar format to the problem shown here? the point is, it can be done either way. Consult any math book's chapters on OoO or DP and you will find similar looking problems that can be done either way, but they tell you which way to solve it. The OP failed to say how to solve it and that's why we have a debate right here.

Oh, and Distributive can be division too:

http://mathforum.org/library/drmath/view/69813.html

[Adi Dusa]

Oh, my god...

I don't intend to be rude, but I surely hope that none of the guys here who are not convinced that the only answer is 288 are/will be working in any safety critical areas. Imagine what would happen if one of them was designing or programming a computer used in a plane to calculate altitude or speed....

First, this is not an equation. It is a simple operation. So leave variables and letters alone. They have no use here. Also, for the guy that tried something like 48/y(x) on his calculator, I believe y(x) is a function, which is a totally different thing than 2(9+3) (I'm not really sure how you wrote it on your calculator, so I admit there is a chance I am not right about it being a function, but then your calculator has a bug and does not know to calculate correctly certain expressions). Also, for those saying that a(b+c) is ab+ac, you have to be aware that a is not 2 here, but 48/2. So, the correct way to split the parentheses is 48/2*9+48/2*3=24*9+24*3=216+72=288.

There are several ways to calculate this, but all will lead to 288...

Second, any symbol you use as an operand (:, /, ?), that is a division and obeys the same rules.

I did not learn in school about PEMDAS or BEMDAS, or whatever you call those, but I did learn about order of operations. It is very simple and I would expect anyone who graduated 4th grade (maybe it depends on the country they went to school in), should know that the result of this operation is 288.

By the way, the post title is incorrect. You do not solve 48?2(9+3), you calculate it. :p

[briangw]

Second, any symbol you use as an operand (:, /, ?), that is a division and obeys the same rules.

I did not learn in school about PEMDAS or BEMDAS, or whatever you call those, but I did learn about order of operations. It is very simple and I would expect anyone who graduated 4th grade (maybe it depends on the country they went to school in), should know that the result of this operation is 288.

Personally, I would perform OoO, but I can see how it can be solved both ways. Not mine, but apparently this debate has been on for some time:

http://answers.yahoo.com/question/index?qid=20110412111826AATGn5S

Okay, the answer is 2, everyone. Look, a math problem can be solved in many different ways, and you?ll get the right answer every single time.

The controversial PEMDAS, BOMDAS way:

48?2(9+3)

48?2(12)

48?24

2

The 2(12) has to be together, not because I?m prioritizing M over D. It is because it is altogether, just as 2x would be. (I will explain this further under substitution.)

DISTRIBUTIVE PROPERTY, which is for those who don?t know, A(B+C)=AB+AC:

48?2(9+3)

48?(2*9+2*3)

48?(18+6)

48?24

2

SUBSTITUTION, which in this case, we will substitute x=(9+3):

48?2x

You don?t do 48?2 first because there?s a variable there and get 24x. First, you find the x:

x=(9+3)

x=12

So, now, you have 2x.

2x=24

48?24

2

If you want to take the SUBSTITUTION further, you can make it that y=48 and x=(9+3).

y?2x

2x is together. The only way y?2 could be a fraction is if it?s (y?2)x.

Another way to use SUBSTITUTION, using PEMDAS/BOMDAS as well: This is why 2(12) is together. Let?s substitute x=12, assuming we have already added what?s in the parenthesis. 9+3=12

48?2x; x=12

You can?t assume that (48?2)x. That?s an entirely different problem. First, you have to find 2x.

2x=24

48?24

2

Using the CALCULATOR, you have to recognize that 2(9+3) is together, so you have to type it like so:

48?(2(9+3))

Otherwise, it naturally assumes you want (48?2)(9+3).

It?s similar to how you use boolean phrases on a computer in terms of computer programming and even a simple Google search. If you want to search for ?new Mexico laws?, as in the Mexico country?s laws, you would type ?new Mexico laws?. But if you want to search US state New Mexico?s laws, you can?t just capitalize the ?n? and assume the computer would recognize the proper noun. (i can just type like this with no capitalization or commas and the computer wouldn?t care.) You have to put parenthesis around ?New Mexico? like so: ??new mexico? laws?. That?s because ?New Mexico? is one whole idea just as 2(9+3) or in substitution, 2x is one whole idea.

WHY 288 IS WRONG:

By COMMUTATIVE PROPERTY, which is AB=BA, those assuming that we have to do the problem LEFT TO RIGHT is also assuming that the problem can be like so:

(48?2)(9+3)

(9+3)(48?2)

12*24

288

If you want to work by THAT, then, you?re assuming that this problem is the same as the original:

9+3(48?2)

9+3(48?2) ? 48?2(9+3)

That?s a completely different problem, and this would get a completely different answer besides 288 and 2. (The answer is 81.)

THE ANSWER IS 2.

[Astra.Xtreme]

Long rant of garbage

For the love of God, how were you ever a teacher? No offense...

By your logic, you are claiming that: 48?2(9+3) = 48?(2(9+3))

It absolutely DOES NOT!

I don't understand why you can't grasp the fact that distributive is multiplication. After executing the numbers inside the parentheses, it wouldn't even make sense to distribute to one number. That goes against the very idea of distribution itself.

It's okay to admit you're wrong...

btw, does this make it any clearer? 48?2*(9+3)

People seem to be very confused when the 2 is right against the (

[Gromit]

Guys, just thought I should clear this up, it's BIDMAS

Brackets

Indicies

Divide

Multiply

Add

Subtract

It's the order if which way to do equations, so you first do the brackets, followed by the indicies, then divide, then multiple, then add then subtract. It's pretty unlikely you'll find them all in one equation but even if not, you do in the order of what operations are in the equation.

[briangw]

For the love of God, how were you ever a teacher? No offense...

By your logic, you are claiming that: 48?2(9+3) = 48?(2(9+3))

It absolutely DOES NOT!

I don't understand why you can't grasp the fact that distributive is multiplication. After executing the numbers inside the parentheses, it wouldn't even make sense to distribute to one number. That goes against the very idea of distribution itself.

It's okay to admit you're wrong...

btw, does this make it any clearer? 48?2*(9+3)

People seem to be very confused when the 2 is right against the (

*sigh* So if I told you to solve 48?2(9+3) using the distributive property can you do it, yes or no? And if no, why? Then in your argument, all of these textbooks are wrong and we should just burn them.

and you obviously missed my edit above where distributitve can work using division:

http://mathforum.org...view/69813.html

[Astra.Xtreme]

Guys, just thought I should clear this up, it's BIDMAS

Brackets

Indicies

Divide

Multiply

Add

Subtract

It's the order if which way to do equations, so you first do the brackets, followed by the indicies, then divide, then multiple, then add then subtract. It's pretty unlikely you'll find them all in one equation but even if not, you do in the order of what operations are in the equation.

Wrong. It's multiply OR divide, then add OR subtract. Going from left to right, whichever comes first.

*sigh* So if I told you to solve 48?2(9+3) using the distributive property can you do it, yes or no? And if no, why? Then in your argument, all of these textbooks are wrong and we should just burn them.

and you obviously missed my edit above where distributitve can work using division:

http://mathforum.org...view/69813.html

If division can be distributed, then so be it. But it still doesn't take away from the fact that you have to follow order of operations from left to right.

There's nothing to be distributed in that problem anyway. If you do distribute, then you completely failed anyway by doing that before the contents of the parentheses...

You act as if all textbooks are 100% correct.

[joint]

lol. all you 288 people are wrong. just think of the size of the number you have to devide by 48 to come up with 288. I also talked to my step brother who is an accountant.. he said if you do 48*1/2*12 thats wrong because if you switch the sign in the beginning you have to do it over on the other side too.. so by doing it your way the correct equation would be 48*1/2*1/12 = 2. So 288 is wrong. 2 is the correct answer. so have a nice day. and like i said just think of the size of the number you have to devide by 48 to come up with 288( doesnt make sense) Have a good day. 2 is the correct answer.

[briangw]

Wrong. It's multiply OR divide, then add OR subtract. Going from left to right, whichever comes first.

If division can be distributed, then so be it. But it still doesn't take away from the fact that you have to follow order of operations from left to right.

There's nothing to be distributed in that problem anyway. If you do distribute, then you completely failed anyway by doing that before the contents of the parentheses...

You act as if all textbooks are 100% correct.

I'm not saying they are correct, but if we go by your logic, then we must not teach students that there can be more than one way to solve a problem based on the directions given. Look, I agree with you that at first glance, I would have used order of operations. I even answered a similar poll on FB choosing the OoO method over the DP one. But at second glance and all the rebuttal going on, I realized that in both scenarios (here and on FB), the only direction given was "Solve." At my first instinct, I chose 288, because that was the logical choice based on what I taught and learned. But then I began to read the other reasonings and started googling this in depth and came up with some pretty interesting stuff. Then, I thought back on the last time I taught (back in November) and considered both chapters and *Bing* it can be done either way.

No one is going to agree to one thing or another, And I won't hold it to you, despite the fact you live in Wisconsin (or maybe just from there). You have some good brats out there, but the Packers can still go to :devil: . It's all good. ;)

[Astra.Xtreme]

lol. all you 288 people are wrong. just think of the size of the number you have to devide by 48 to come up with 288. I also talked to my step brother who is an accountant.. he said if you do 48*1/2*12 thats wrong because if you switch the sign in the beginning you have to do it over on the other side too.. so by doing it your way the correct equation would be 48*1/2*1/12 = 2. So 288 is wrong. 2 is the correct answer. so have a nice day. and like i said just think of the size of the number you have to devide by 48 to come up with 288( doesnt make sense) Have a good day. 2 is the correct answer.

Do you even know what you are talking about? You completely disregarded the ordering notion of the problem, which is the whole point of it in the first place...

I'm an engineer, and I say that the answer is 288 because of the grade school-level laws of mathematics. Not that my profession has anything to do with it anyway...

No one is going to agree to one thing or another, And I won't hold it to you, despite the fact you live in Wisconsin (or maybe just from there). You have some good brats out there, but the Packers can still go to :devil: . It's all good. ;)

We take pride in our beer. :)

At least you didn't mention the world's worst basketball team, the Bucks. :x And the fact that our weather sucks. Can't beat a 35 degree rain all through spring. heh

[joint]

Do you even know what you are talking about? You completely disregarded the ordering notion of the problem, which is the whole point of it in the first place...

I'm an engineer, and I say that the answer is 288 because of the grade school-level laws of mathematics. Not that my profession has anything to do with it anyway...

i feel sorry for the things that you enginner

yes i do. 48/?=288 ?=13824 someone explain how you get 13,824 from 2(9+3) Lol

[Hardcore Til I Die]

lol. all you 288 people are wrong. just think of the size of the number you have to devide by 48 to come up with 288. I also talked to my step brother who is an accountant.. he said if you do 48*1/2*12 thats wrong because if you switch the sign in the beginning you have to do it over on the other side too.. so by doing it your way the correct equation would be 48*1/2*1/12 = 2. So 288 is wrong. 2 is the correct answer. so have a nice day. and like i said just think of the size of the number you have to devide by 48 to come up with 288( doesnt make sense) Have a good day. 2 is the correct answer.

The fact that your Stepbrother's an Accountant is irrelevant. He probably doesn't have to solve problems like this one every day. Plus, this sort of thing is taught in Primary School/early Secondary School, so any old school student is just as qualified to comment on the answer to this question as an Accountant is.

The answer is 288.

i feel sorry for the things that you enginner

yes i do. 48/?=288 ?=13824 someone explain how you get 13,824 from 2(9+3) Lol

What on earth are you walking about? How can 48/13824 = 288? :unsure:

I think you've lost the plot mate :p

[joint]

The fact that your Stepbrother's an Accountant is irrelevant. He probably doesn't have to solve problems like this one every day. Plus, this sort of thing is taught in Primary School/early Secondary School, so any old school student is just as qualified to comment on the answer to this question as an Accountant is.

The answer is 288.

the correct answer to this problem is 2. its ok that you are all wrong. at least you learned something though

[Ambroos]

Mathematics should be clear to avoid any confusion. This thing is unclear because it could give a different result depending on what 'conventions' you follow. Left-to-right and the juxtapositioning rule are two different conventions that both aren't accepted everywhere. This makes the original equitation ambiguous, and ambiguity in math is just not allowed. When in doubt, add more brackets, it's always been like that.

[Hardcore Til I Die]

the correct answer to this problem is 2. its ok that you are all wrong. at least you learned something though

Yeah I learnt that not all Accountants are good at Maths. Who'd have thought?

[briangw]

We take pride in our beer. :)

At least you didn't mention the world's worst basketball team, the Bucks. :x And the fact that our weather sucks. Can't beat a 35 degree rain all through spring. heh

lol. Well, we have a pretty bad team in the Timberwolves too. I do admit, I like your beer and we 've had a couple of 35 degree rain showers in NW MN. I still find it funny that the Twin Cities got more snow than we did up north this season.

[joint]

The fact that your Stepbrother's an Accountant is irrelevant. He probably doesn't have to solve problems like this one every day. Plus, this sort of thing is taught in Primary School/early Secondary School, so any old school student is just as qualified to comment on the answer to this question as an Accountant is.

The answer is 288.

What on earth are you walking about? How can 48/13824 = 288? :unsure:

I think you've lost the plot mate :p

whatever i typed it in the wrong order. the point is still the same.... think of the size of the number 48 is deviding by to come up with an answer of 288. that number is huge. 13824/48=288. explain where 13824 comes from 2(9+3). OTHERWISE THIS TOPIC IS OVER. THE SOLUTION IS 2. BY YOUR WAY THE CORRECT PROBLEM WOULD BE 48*1/2*1/12 = 2.

[Calum Veteran]

Wow, 27 pages for a sum that clearly calculates to 288? :blink:

[Hardcore Til I Die]

whatever i typed it in the wrong order. the point is still the same.... think of the size of the number 48 is deviding by to come up with an answer of 288. that number is huge. 13824/48=288. explain where 13824 comes from 2(9+3). OTHERWISE THIS TOPIC IS OVER. THE SOLUTION IS 2. BY YOUR WAY THE CORRECT PROBLEM WOULD BE 48*1/2*1/12 = 2.

Nothing is divided by 48 though?? I don't understand where you're getting that from...

(9+3) = (12)

48 / 2 = 24

24(12) = 24*12 = 288

Nothing is ever divided by 48 so I don't understand what you mean by that.

[Astra.Xtreme]

whatever i typed it in the wrong order. the point is still the same.... think of the size of the number 48 is deviding by to come up with an answer of 288. that number is huge. 13824/48=288. explain where 13824 comes from 2(9+3). OTHERWISE THIS TOPIC IS OVER. THE SOLUTION IS 2. BY YOUR WAY THE CORRECT PROBLEM WOULD BE 48*1/2*1/12 = 2.

You still don't have any idea what you're talking about... Where are you getting this idea of some huge number 48 is dividing? You are comparing a plain division with this problem that has precise ordering. It's completely different.

Anybody that thinks the answer is 2, is saying that 48/2(9+3) = 48/(2(9+3)).

It's not, and you can never say otherwise...

[Ambroos]

Wow, 27 pages for a sum that clearly calculates to 288? :blink:

You disappoint me Callum, I've always liked you, but now you're clearly wrong :p Juxtaposition implies that you execute 2(12) before you do 48/2 :p

Oh well, I'm never gonna get this explained :p