[tex]\it{x:y=3\ rest 7
}[/tex]
Aplicam teorema impartirii cu rest si obtinem relatiile :
[tex]\it{x=3y+7\ \ \ \ (1)}[/tex]
[tex]\it{y\ \textgreater \ 7\ \ \ \ (2)}[/tex]
Acum avem:
[tex]\it{y\ \textgreater \ 7|_{\cdot3}\Longrightarrow 3y\ \textgreater \ 21|_{+7}\Longrightarrow 3y+7\ \textgreater \ 28\stackrel{(1)}{\Longrightarrow} x\ \textgreater \ 28}[/tex]
Deci:
[tex]x\ \textgreater \ 28\ si\ y\ \textgreater \ 7\Longrightarrow \ x+y\ \textgreater \ 28+7 \Longrightarrow \ x+y\ \textgreater \ 35 .[/tex]