[tex]\it (\overline{abc} - \overline{bc})\ \vdots\ 100[/tex]
[tex]\it \overline{abc} - \overline{bc} = 100a+10b+c-(10b+c) =
\\\;\\
\it=100a+(10b+c)-(10b+c)=100a \in M_{100} \Longrightarrow[/tex]
[tex]\it \Longrightarrow(\overline{abc} - \overline{bc})\ \vdots\ 100 .[/tex]
