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Elementary Math Fractions, Percentages, Word Problems, Equations, Inequations, Factorization, Expansion


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September 28th, 2019, 02:54 AM   #1
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proof

abc and bca are 3 digit numbers.show that abc-cba is divided by 11
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September 28th, 2019, 04:51 AM   #2
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If I let a=b=c, I seem to be getting a funny result.
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September 28th, 2019, 05:06 AM   #3
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321 - 213 = 108 where 108 is not divisible by 11.
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September 28th, 2019, 09:42 AM   #4
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But 321 - 123 = 198 which is divisble by 11.

\begin{align}
(100a + 10b + c) - (100c + 10b + a) &= 99a - 99c \\
&= 11( 9a-9c)
\end{align}

I have no idea what bca has to do with the price of fish.
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Last edited by v8archie; September 28th, 2019 at 09:46 AM.
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September 28th, 2019, 01:20 PM   #5
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it is abc-cba
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