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Replies: 26
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All-In [45784]
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This might be to hard for a coot
Mar 5, 2020, 5:50 AM
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All-In [40344]
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7***
Mar 5, 2020, 5:58 AM
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All-In [48078]
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Re: 7***
Mar 5, 2020, 6:08 AM
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I came up with 2.
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All-In [40344]
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I was going with the typical jounge answer
Mar 5, 2020, 6:25 AM
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Depending on how you were taught you’ll get different answers
I was taught PEMDAS like everybody else. We did the PE and then moved left to right on MD and then the same on AS.
Others were taught that M came before D then A and finally S
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Oculus Spirit [93673]
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Close enough for government work.***
Mar 5, 2020, 11:51 AM
[ in reply to 7*** ] |
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All-In [48078]
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Re: This might be to hard for a coot
Mar 5, 2020, 5:59 AM
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Obviously
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Heisman Winner [105622]
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Sixteen***
Mar 5, 2020, 6:48 AM
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All-In [26968]
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The implied multiplication between the 2
Mar 5, 2020, 7:02 AM
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and the (2+2) makes me want to do that first. It's like it's stressing that the 2 is supposed to be paired with the parenthetical. But I don't know what the "official" right answer is, if there even is one.
If you do it that way, then the answer is 1.
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Heisman Winner [105622]
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That is the trick. After you do the 2+2 in the parenthesis,
Mar 5, 2020, 7:06 AM
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you just have multiplication and division left which are considered the same from order of operations and therefore you just go left to right.
8/2=4
4*4=16
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All-In [26968]
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Who decided "left-to-right," though? Like, is there
Mar 5, 2020, 7:41 AM
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an emperor of mathematics who decided this?
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Heisman Winner [105622]
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President Benjamin Franklin declared it at the Battle
Mar 5, 2020, 7:42 AM
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of Appomattox
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All-In [49175]
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yup. He decided Chinese was too hard to read, and we were
Mar 5, 2020, 8:03 AM
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going to go in a different direction.
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Heisman Winner [105622]
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Exactly!
Mar 5, 2020, 8:19 AM
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Left to Right versus Right to Left
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Heisman Winner [137976]
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1.
Mar 5, 2020, 8:02 AM
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Parentheses override all else.
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Heisman Winner [105622]
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WRONG***
Mar 5, 2020, 8:20 AM
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All-In [45784]
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Re: 1.
Mar 5, 2020, 10:28 AM
[ in reply to 1. ] |
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All-In [29036]
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Nope
Mar 5, 2020, 10:33 AM
[ in reply to 1. ] |
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8 / 2(2 + 2) <-- resolve inside parens
8 / 2(4) <-- Current accepted mathematical practice is to consider implied multiplication as
simple multiplication (this wasn't always the case, but has been for 50 years
or so). So this can be written as...
8 / 2 * 4 <-- Mult and Div are done left to Right in sequence
4 * 4 <-- And continue
16
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Oculus Spirit [81078]
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If this was re-stated in variables the answer would be 1
Mar 5, 2020, 11:03 AM
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lets say: x divided by 2 (y+y), where x=8, and y=2, the answer would necessarily be 1.
x/2(y+y), or x over 2(2y)
8/8
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All-In [26968]
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Yes.***
Mar 5, 2020, 11:49 AM
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Oculus Spirit [81078]
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Thats why I'm not sure why its different w/o variables***
Mar 5, 2020, 11:51 AM
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All-In [29036]
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Nope, you make a leap
Mar 5, 2020, 11:57 AM
[ in reply to If this was re-stated in variables the answer would be 1 ] |
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x/2(y+y) does not equal x over 2(2y) or
x
-------
2(y+y)
Because we resolve multiplication/division left to right x/2(y+y) actual means:
x xy xy
--- * (y+y) ==> ---- + ---- ==> xy ==> x*y ==> 16 (for x=8, y=2)
2 2 2
You've added a paren structure in your reading of x/2(y+y). You are interpreting it as x/(2(y+y)).
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All-In [29036]
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I should add that the form of the original formula
Mar 5, 2020, 12:03 PM
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Is intentionally ambiguous. There are accepted suggestions in place to break that ambiguity, but the real answer for anyone actually interested in math is to write the formula to more clearly state what the intention is.
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All-In [26968]
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Who was this person who decided this 50 years ago
Mar 5, 2020, 11:50 AM
[ in reply to Nope ] |
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Do they have an e-mail address?
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All-In [29036]
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It wasn't a singular person
Mar 5, 2020, 12:16 PM
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But rather a consensus of mathematicians attempting to remove ambiguity from written formulas. But as I said before the real solution is to write your formulas in an entirely unambiguous way.
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CU Medallion [60043]
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Re: Nope
Mar 5, 2020, 12:20 PM
[ in reply to Nope ] |
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I am probably the worst person on this board when it comes to math and I even got this one right.
Thanks to Thom and Greenr for making me feel better about my maths.
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Orange Blooded [2618]
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Re: This might be to hard for a coot
Mar 5, 2020, 12:17 PM
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C Always pick C when you are unsure.
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Lot o points [163012]
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16 per Excel
Mar 5, 2020, 4:15 PM
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50
