Răspuns :

Salutare!

[tex] \bf \overline{aaa} + \overline{aa} + \overline{a} = 246[/tex]

Descompunem in baza zece:

[tex] \bf 100a + 10a + a + 10a + a + a = 246[/tex]

[tex]\bf 123a = 246 \: \Big| :123[/tex]

[tex] \boxed{\bf a = 2}[/tex]

[tex]\it Verificare: 222 + 22 + 2 = 246[/tex]