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Let it go. -5 leaves you with 95. 95 isn't that bad of a grade.
NOT GOOD ENOUGH!
Quote:
Originally Posted by NJBest
I wonder what he/she took points off for. Did you forget to name and date?
Well considering mah name is on the post and there's a post date, I do believe so! :3
Though, it's probably the concept of implied multiplication that's throwing people off. Implied multiplication, strict usage of PEDMAS/PEMDAS/etc, and single-line equations don't mix. Then again, implied multiplication is silly. This is math, not poetry.
If say x=12 and the equation was 48 ÷ 2x, one would automatically write 48÷2(12) then 48÷24 then 2. Except, in my math classes, it would have started with having a correctly written question:
48
2x
to
48
2(12)
to
48
24
to
2
OR
48 * x
2
to
24x
to
24(12)
to
288
Last edited by gallowsCalibrator; 09-23-2011 at 02:16 PM..
This is an incredibly entertaining thread. I did not read back all the 29 pages but was distributive property of multiplication mentioned ?
Distributive property of multiplication states 2(9+3) cannot be separated
2(9+3) = (2*9 + 2*3).
The 2 outside of the parenthesis follows the distributive property of multiplication and must be factored and simplified before performing any other operations on it. You have to use Algebra to simplify the 2(9+3) before applying computing expression PEMDAS from left to right.
48 ÷ 2(9+3) =
48 / (2*9 + 2*3) =
48 / 24 = 2 ~~~Answer = 2 ~~~
Any calculator be it auto or manual such as Excel, Google do not understand theorems or properties and depend on you to explicitly explain what you want computed. Garbage in garbage out.
48 / 2 * (9+3) is NOT equal to 48 / 2(9+3).
48 / 2 * (9+3) = 48 / 2 * 1(9+3) is NOT equal to 48 / 2(9+3) = 48 / (2*9+2*3).
This is an incredibly entertaining thread. I did not read back all the 29 pages but was distributive property of multiplication mentioned ?
Distributive property of multiplication states 2(9+3) cannot be separated
2(9+3) = (2*9 + 2*3).
The 2 outside of the parenthesis follows the distributive property of multiplication and must be factored and simplified before performing any other operations on it. You have to use Algebra to simplify the 2(9+3) before applying computing expression PEMDAS from left to right.
48 ÷ 2(9+3) =
48 / (2*9 + 2*3) =
48 / 24 = 2 ~~~Answer = 2 ~~~
Any calculator be it auto or manual such as Excel, Google do not understand theorems or properties and depend on you to explicitly explain what you want computed. Garbage in garbage out.
48 / 2 * (9+3) is NOT equal to 48 / 2(9+3).
48 / 2 * (9+3) = 48 / 2 * 1(9+3) is NOT equal to 48 / 2(9+3) = 48 / (2*9+2*3).
Final Answer : 2
Do I move to top of class ?
Yes you do. It has been argued that in order for 2(9+3) to be considered a single expression that an additional set of parentheses would be required. However, under the conventions, that would be redundant, since it alreay is considered to be an single expression and is not to be taken as separated. I think that this little exercise causes such a dispute is because it is mixing types of syntax so to speak. The "48 ÷ 2(9+3)" should not be used with the "÷" but rather "/". It is set up for that purpose. Do a google on the expression and you will find it on pages dedicated to this very subject. Alacran and Jtur88 nailed the explanation.
The "48 ÷ 2(9+3)" should not be used with the "÷" but rather "/". It is set up for that purpose. Do a google on the expression and you will find it on pages dedicated to this very subject. Alacran and Jtur88 nailed the explanation.
Ok, this is a whole different realm I have no details into besides old school traditions symbol before advent of computers. It's crummy to type ALT+0247 vs "/" . Well maybe I was educated in simpler times
Ok, this is a whole different realm I have no details into besides old school traditions symbol before advent of computers. It's crummy to type ALT+0247 vs "/" . Well maybe I was educated in simpler times
Link to evidence?
Because last I checked, distributive property of multiplication is just multiplication still subject to the proper order of operations.A pretty basic lesson that includes distributive property.
You quoted a part of my original post explanation . Here's the relevant portion with comment in bold
Solve
48 ÷ 2(9+3)
Distributive property of multiplication states 2(9+3) cannot be separated . ie the "2" cannot be separated from the (9+3) . You have to use Algebra to simplify the 2(9+3) before applying computing expression PEMDAS from left to right.
and computing like this below is incorrect
48 ÷ 2(9+3) ≠ (48÷2) * 12 =288 ---> WRONG ANSWER
CASE IN POINT - we cannot separate the "2" from the expression "2(9+3)" in solving this problem 48 ÷ 2(9+3)
----------------------------------------------------------------------------------------------------------------------
going on to your new example
Quote:
Originally Posted by Rita Mordio
8 + 2(6 – 2) ÷ 4
First, I simplify the expression in parentheses:
8 + 2(4) ÷ 4
Then, I do all my multiplications and divisions in order from left to right:
8 + 8 ÷ 4
8 + 2
Finally, I do my addition:
10
Most including myself will solve it as you have stated above. The distributive multiplication property explains that the "2" belongs together with 2(6-2)
Applying distributive multiplication/PEMDAS it works out to the same answer as above
8 + (2*6 - 2*2) ÷ 4
8 + (12 - 4) ÷ 4
8 + 8 ÷ 4
8 + 2
10
In "real world", why would one express a number as 2(9+3)? The (9+3) portion would have been mentally added easily and expressed as (2*12). Well think elementary grade school multiplication. Ask a 3rd grader to solve 2*12, they might tell you 'but i have not work on numbers greater than 10 yet'. Well easily resolve if we explain the same expression as 2(9+3) or 2(6+6) or 2(10+2)..... My kids were taught this method of approaching a large number problem in elementary school.
Distributive multiplication also comes in useful when solving algebraic expression as this 2(9x + 3). We can't combine the 9x and the 3. But, suppose this expression showed up in an equation like: 2(9x + 3) = 6 , we can solve for x by apply the distributive multiplication property .
CASE IN POINT - we cannot separate the "2" from the expression "2(9+3)" in solving this problem 48 ÷ 2(9+3)
OMG! This is still being debated? The answer is NOT 2!!! It is 288. If you think otherwise, you are simply wrong and need to go review some simple algebra and order of precedence.
Quote:
Originally Posted by Rita Mordio
I can't believe people are still arguing over this.
It really is simple algebra.
48÷2(9+3) = 48 x 0.5 x (9+3) = 48 x 0.5 x 12 = 24 x 12 = 288
Quote:
Originally Posted by js1mom
Oh God!!! Nightmares really DO come true!!! A whole thread devoted to the solution of ONE algebra problem.... AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!
I have been of the opinion that when it comes to letters and numbers- never the twain should meet.
The irony of your snickering at the simpletons who don't understand simple mathematical constructs is that this is not an algebraic problem, it is an arithmetic problem. If it were an algebraic problem, those who advocate for the supremacy of the implied multiplication/distributive function would actually have a stronger case for the answer being 2.
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