My Math Forum proof

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

 September 28th, 2019, 02:54 AM #1 Newbie   Joined: Sep 2019 From: ireland Posts: 3 Thanks: 0 proof abc and bca are 3 digit numbers.show that abc-cba is divided by 11
 September 28th, 2019, 04:51 AM #2 Senior Member   Joined: Jun 2014 From: USA Posts: 620 Thanks: 52 If I let a=b=c, I seem to be getting a funny result.
 September 28th, 2019, 05:06 AM #3 Senior Member   Joined: Jun 2014 From: USA Posts: 620 Thanks: 52 321 - 213 = 108 where 108 is not divisible by 11. Thanks from topsquark
 September 28th, 2019, 09:42 AM #4 Math Team   Joined: Dec 2013 From: Colombia Posts: 7,690 Thanks: 2669 Math Focus: Mainly analysis and algebra 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. Thanks from idontknow Last edited by v8archie; September 28th, 2019 at 09:46 AM.
 September 28th, 2019, 01:20 PM #5 Senior Member   Joined: Mar 2015 From: Universe 2.71828i3.14159 Posts: 132 Thanks: 49 Math Focus: Area of Circle it is abc-cba Thanks from idontknow

 Tags proof

 Thread Tools Display Modes Linear Mode

 Contact - Home - Forums - Cryptocurrency Forum - Top