# Math Help - Stumped on a Proof

1. ## Stumped on a Proof

Prove that every 6-digit integer of the form abcabc (ex. 241241, 638638) is divisible by 13.

2. The decimal expansion of $abcabc$, is $a\cdot10^5+b\cdot10^4+c\cdot10^3+a\cdot10^2+b\cdot 10+c=10^3(a\cdot10^2+b\cdot10+c)+a\cdot10^2+b\cdot 10+c$.