

X-3/x-1=x-4/x-5 - anigbrowl
http://www.bing.com/search?q=x-3/x-1%3Dx-4/x-5&go=&form=QBLH&scope=web&qs=n

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anigbrowl
In other words, bing now has some calculation abilities. MS is running an ad
with this particular calculation suggested as a Bing search and a background
photo of a blackboard.

Well, as you see, it works. And (I presume) they would like you think about
the fact that throwing the same equation at Google does nothing useful
(inexplicably, the first result was a page about BSD).

But I wonder how many users of this feature will be familiar with the rules of
operator precedence? I admit I read it as:

x-3

\--- = ... << I can't format it right but you get the idea

x-1

After testing it with Google, I went to Alpha, which (unsurprisingly) handled
it with aplomb, giving it to me with proper notation as well and making me
aware of my mistake. So I tried it as (x-3) / (x-1) = (x-4) / (x-5), which
Alpha also handled with Aplomb (11/3 if you are lazy).

However, inputing the latter into Bing (without or without spaces for padding)
gave no calculation or result, but just a bunch of (mostly unrelated) search
results. Seems rather counter-productive on MS's part.

Apologies if this is excessively trivial.

~~~
anigbrowl
Even weirder...

(x-3)/x-1=(x-4)/x-5 works OK (ie Bing treats it as math); indeed for
(x-3)/x-1=x-4/x-5 Bing properly gives both solutions 1/2(5+/-(29^0.5)).

But it absolutely Does Not Like parentheses in denominator (eg
x-3/(x-1)=x-4/x-5) on either side of the equation. Clearly, I need to get out
more.

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skoob
For some reason, it only works for certain combinations of countries and
languages. E.g., it works for Argentina:
[http://www.bing.com/search?q=x-3%2fx-1%3dx-4%2fx-5&setmk...](http://www.bing.com/search?q=x-3%2fx-1%3dx-4%2fx-5&setmkt=es-
AR) but not Chile:
[http://www.bing.com/search?q=x-3%2fx-1%3dx-4%2fx-5&setmk...](http://www.bing.com/search?q=x-3%2fx-1%3dx-4%2fx-5&setmkt=es-
CL)

~~~
fsniper
And not for Turkey..

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jerf
Please don't post homework problems to this newsgroup.

~~~
anigbrowl
Oh dear, I hope that's a joke :-/ Maybe I should have done it as a 'tell HN'
type post. I thought people would be interested in the depth of the parsing
tree.

~~~
jerf
Yes. I thought "newsgroup" would be a giveaway. :-/ No usenetters here, eh?

'course, people may just not like the joke.

~~~
icey
I had a comp.lang.lisp flashback, so I'll say you did a good job :D

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Pistos2
FWIW: <http://www.numberempire.com/equationsolver.php> says -1/4. It will only
give 11/3 if you explicitly put parentheses: (x-3)/(x-1)=(x-4)/(x-5) . So I
believe Bing's result is correct. Based on elementary school order of
operations, the implied parentheses on the original equation are: x - (3/x) -
1 = x - (4/x) - 5.

------
g_
I don't see the result in Bing.

alpha direct link:
[http://www.wolframalpha.com/input/?i=(x-3)/(x-1)%3D(x-4)/(x-...](http://www.wolframalpha.com/input/?i=\(x-3\)/\(x-1\)%3D\(x-4\)/\(x-5\))

~~~
michaelkeenan
Are you outside the USA? I'm in Taiwan and Bing isn't calculating it for me
either. It's just returning a bunch of normal search results in Chinese. Maybe
calculation only works for queries coming from inside the USA.

~~~
chaosprophet
Well, I'm in India and it does display the calculations for me.

~~~
ivanstojic
I'm in Croatia and it's not returning calculations for me. It seems only
select locations got this enabled in the first run...

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zach
To be fair:

<http://www.wolframalpha.com/input/?i=southernmost+us+capital>

~~~
sp332
Washington, DC is the only US capital.

~~~
redcap
Surely state capitals count as capitals in the US?

~~~
sp332
Those are state capitals, not US capitals. Though I guess you could make the
case that America has 3 capitals: U - S - A!

------
cema
An interesting, apparently unintentional, side effect is the exercise in the
precedence rules.

Search engines (bing, google, wolfram) get the precedence but are finicky
about calculations. Humans (presumable anyway, from the earlier comments) do
the calculations but sometimes overlook the precedences. I think it is rather
funny.

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adatta02
Live! search could do these types of calculations for sometime. It could even
handle solving quadratics.

~~~
seldo
Live search had an integrated exclamation point in the name?

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anulman
x = 11/3

~~~
mark-t
No, x = -1/4 is correct. Perhaps you should look up the order of operations.

~~~
redcap
I'm getting x = 11/3 as well.

My workings:

(x-3)/(x-1) = (x-4)/(x-5)

(x-3)(x-5) = (x-4)(x-1)

x^2 -8x + 15 = x^2 -5x +4

-8x + 11 = -5x

11 = 3x

x = 11/3

FWIW, wolfram alpha agrees with me.

~~~
bobbyi
You changed the equation.

You started with

(x-3)/(x-1) = (x-4)/(x-5)

which is not the same as

x - 3/x - 1 = x - 4/x - 5

, the equation in the submission.

~~~
redcap
Haha, thanks - I guess the problem is in my parsing :)

