# Divisibilty related problem

1. Apr 4, 2012

### sparsh12

if,

10x+1 divides n-x

and 10x +1 divides 10n +1 , where x is a variable and positive integer while n is a constant and positive integer.

then, is there a way to find, of what form x must be, in terms of 'n' ?

2. Apr 4, 2012

### chiro

Hey sparsh12 and welcome to the forums.

Have you dealt with linear systems of congruence equations? Do you know how to solve linear congruence equations? Have you heard of the chinese remainder theorem?

3. Apr 4, 2012

### sparsh12

--> Yeah i have heard of Chinese remainder theorem but i have never dealt with linear systems of congruence equations.

--> And i observed that both congruences are actually equivalent, so i feel the problem doesnot remain a system of congruence equation, as i infer from it's name.

--> But the problem remains unsolved for me.

--> Apart from all that i have a book of elementary number theory by David Burton.i would try to go through it.

4. Apr 4, 2012

### sparsh12

Last edited by a moderator: May 5, 2017