Solve 48

[webeagle12]

Solve 48?2(9+3)

post answers and why :p

[Squirrelington]

Paren. first so 9+3 = 12

48/2*12

order suggest LTR now so 48/2 = 24

24*12 is all thats left and equals 288

[fhpuqrgrpgvirzhpujbj]

The OoO there got me for a second but if you follow them properly I'd have to agree with the above poster.

I think the natural tendency is to multiply the 2 and the 12 and end up at 2 for whatever reason.

[mail]

Order of operations.

[The_Decryptor Veteran]

Paren. first so 9+3 = 12

48/2*12

order suggest LTR now so 48/2 = 24

24*12 is all thats left and equals 288

This is the only proper way to do it, unless you believe in a different form of maths.

[mail]

Order of operations.

[Denis W. Veteran]

At first I thought of 2, but now that you mention it... BEDMAS is there for a reason, so yeah it would be 24 * 12.

[Draconian Guppy]

?? there's no way around it...division always goes first, then multiplication Ergo:

24*12 = 288

Now... if it were fractions... say 48/2(9+3), it's a whole different story.. you'd get 48/24 = 2. But based on the above premise, the answer is 288.

[zeta_immersion]

All you need to do is apply the rules, there is no trick ...

first do the brackets (9+3) = 12

then do the division 48/2=24

and finally 12*24 = whatever

so the answer is whatever

Please note as there are no brackets between 48, 2 you cannot and should not assume the expression is something like this 48/[2*(9+3)] or any other combination

(Edit: 48/2 != 12 my bad)

[AimLXJ]

All you need to do is apply the rules, there is no trick ...

first do the brackets (9+3) = 12

then do the division 48/2=12

and finally 12*12 = 144

so the answer is 144

Please note as there are no brackets between 48, 2 you cannot and should not assume the expression is something like this 48/[2*(9+3)] or any other combination

What? :blink:

[riceBox]

All you need to do is apply the rules, there is no trick ...

first do the brackets (9+3) = 12

then do the division 48/2=12 24

and finally 1224*12 = 144 288

so the answer is 144 288

Please note as there are no brackets between 48, 2 you cannot and should not assume the expression is something like this 48/[2*(9+3)] or any other combination

Fixed it for you. :)

[Darksoft]

lol

somebody's been browsing 4chan

anyways

288 (PEMDAS)

[leedogg]

48/2(9+3) = 48/2(a+b) = 48/(2a + 2b)

NOT 24(a+b)

The answer is 2 based on the distributive law of multiplication taking precedence. If you want to know how PEMDAS factors in, you can just say that the digit next to the parentheses directly acts on the elements within the parentheses and therefore it's factored in before the rest of the order of operations.

[Stetson]

?? there's no way around it...division always goes first, then multiplication Ergo:

24*12 = 288

Now... if it were fractions... say 48/2(9+3), it's a whole different story.. you'd get 48/24 = 2. But based on the above premise, the answer is 288.

Division and multiplication are equal, you do them left to right.

48/2(9+3) = 48/2(a+b) = 48/(2a + 2b)

NOT 24(a+b)

The answer is 2 based on the distributive law of multiplication taking precedence. If you want to know how PEMDAS factors in, you can just say that the digit next to the parentheses directly acts on the elements within the parentheses and therefore it's factored in before the rest of the order of operations.

Nope. http://www.wolframalpha.com/input/?i=48%C3%B72%289%2B3%29

Distribution is just multiplication. 48/2(9+3) is the same as 48/2*(9+3)

You calculate inside the parentheses first, and then you do the multiplication and division from left to right. Your explanation does a multiplication on right before the division on the left.

[The_Decryptor Veteran]

2 * (9+3) is the same as 2*9 + 2*3, it doesn't change the outcome.

[leedogg]

Nope. http://www.wolframalpha.com/input/?i=48%C3%B72%289%2B3%29

Distribution is just multiplication. 48/2(9+3) is the same as 48/2*(9+3)

You calculate inside the parentheses first, and then you do the multiplication and division from left to right. Your explanation does a multiplication on right before the division on the left.

This next example displays an issue that almost never arises but, when it does, there seems to be no end to the arguing.

Simplify 16 ? 2[8 ? 3(4 ? 2)] + 1.

16 ? 2[8 ? 3(4 ? 2)] + 1

= 16 ? 2[8 ? 3(2)] + 1

= 16 ? 2[8 ? 6] + 1

= 16 ? 2[2] + 1 (**)

= 16 ? 4 + 1

= 4 + 1

= 5

The confusing part in the above calculation is how "16 divided by 2[2] + 1" (in the line marked with the double-star) becomes "16 divided by 4 + 1", instead of "8 times by 2 + 1". That's because, even though multiplication and division are at the same level (so the left-to-right rule should apply), parentheses outrank division, so the first 2 goes with the [2], rather than with the "16 divided by". That is, multiplication that is indicated by placement against parentheses (or brackets, etc) is "stronger" than "regular" multiplication. Typesetting the entire problem in a graphing calculator verifies this hierarchy:

Note that different software will process this differently; even different models of Texas Instruments graphing calculators will process this differently. In cases of ambiguity, be very careful of your parentheses, and make your meaning clear. The general consensus among math people is that "multiplication by juxtaposition" (that is, multiplying by just putting things next to each other, rather than using the "?" sign) indicates that the juxtaposed values must be multiplied together before processing other operations. But not all software is programmed this way, and sometimes teachers view things differently. If in doubt, ask!

http://www.purplemath.com/modules/orderops2.htm

[Stetson]

http://www.purplemath.com/modules/orderops2.htm

So basically the conclusion is that there is no universally agreed-upon rule. Sounds about right to me. I can see some high level math professors caring about this, but then again they would probably criticize you for not being clearer if you were to write such an equation. Simply adding another pair of parentheses makes it much clearer for everyone following along or grading your work.

In practice you would probably write the equation as either or . The first one would calculate to 288 and the second would calculate to 2, since the second equation is the same as 48/[2(9+3)].

[Ulpian]

Short version: Solve 2+2*2=?

Still some people make mistakes :)

[mauriziocorso77]

So basically the conclusion is that there is no universally agreed-upon rule. Sounds about right to me. I can see some high level math professors caring about this, but then again they would probably criticize you for not being clearer if you were to write such an equation. Simply adding another pair of parentheses makes it much clearer for everyone following along or grading your work.

In practice you would probably write the equation as either or . The first one would calculate to 288 and the second would calculate to 2, since the second equation is the same as 48/[2(9+3)].

The above post is correct.

The way it is written in the original post, would mean the answer is 2 as there would need to be brackets between 48 and 2 to give 288. You are all multiplying by 12 when you should be multiplying by 1/12.

[The_Decryptor Veteran]

The confusing part in the above calculation is how "16 divided by 2[2] + 1" (in the line marked with the double-star) becomes "16 divided by 4 + 1", instead of "8 times by 2 + 1". That's because, even though multiplication and division are at the same level (so the left-to-right rule should apply), parentheses outrank division, so the first 2 goes with the [2], rather than with the "16 divided by". That is, multiplication that is indicated by placement against parentheses (or brackets, etc) is "stronger" than "regular" multiplication. Typesetting the entire problem in a graphing calculator verifies this hierarchy:

I don't see why this is confusing, brackets come first, so of course 2(2) is worked out before the division.

I assume I'm missing something though, since 16 / 2(2) seems obvious to me.

[Stetson]

The above post is correct.

The way it is written in the original post, would mean the answer is 2 as there would need to be brackets between 48 and 2 to give 288. You are all multiplying by 12 when you should be multiplying by 1/12.

Right, but that relies on a little-known rule of presidence. You'd be much better off writing it as 48/(2(9+3) or with the 48 over 2(9+3) since that implies the extra parentheses. 48/2(9+3) is an unnecessarily confusing way to write it, as you can see by the many back-and-forth posts here and everywhere else this gets posted. :p

I don't see why this is confusing, brackets come first, so of course 2(2) is worked out before the division.

I assume I'm missing something though, since 16 / 2(2) seems obvious to me.

The confusion isn't whether parentheses come before division, everyone agrees that the (9+3) gets done first. The interesting part is the difference between 2(9+3) and 2*(9+3). They are very close to being the same thing, and most people probably wouldn't know that there is a presidence difference between them. I've never had this particular case come up in practice because like I've said this is a strange way to write that equation, but I've never been taught that there was any difference between 2(9+3) and 2*(9+3).

[primexx]

I don't see why this is confusing, brackets come first, so of course 2(2) is worked out before the division.

I assume I'm missing something though, since 16 / 2(2) seems obvious to me.

brackets come first applies to things inside the bracket. it doesn't tag things outside along with it.

consider x/y(z) and x/y*(z). they should evaluate to the same result.

[Stetson]

brackets come first applies to things inside the bracket. it doesn't tag things outside along with it.

consider x/y(z) and x/y*(z). they should evaluate to the same result.

Not according to the rule posted above. The first would evaluate to x/yz and the second would evaluate to (x/y)z. It's so little-known though that I believe even a TI-85 calculator gets it wrong.

[Quixote87]

Answer: 42

Reason: It is the answer to life, the universe, and everything

[primexx]

Not according to the rule posted above. The first would evaluate to x/yz and the second would evaluate to (x/y)z. It's so little-known though that I believe even a TI-85 calculator gets it wrong.

and it makes no sense. also consider the following:

x / y(z)

x / y * 1(z)

according to those "rules" they would result in different answers.