Răspuns:
Explicație pas cu pas:
[tex]ab-ba=a\\\\10a+b-(10b+a)=a\\\\10a+b-10b-a=a\\\\9a-9b=a\\\\9(a-b)=a= > a=9\\\\b=8\\ \\98-89=9\\\\nr.ab=98[/tex]
