Question

determinati numerele de forma ab(in baza zece) , stiind ca ab1+3ba+ab4=851(tot in baza zece)

Answer 1

ab1+3ba+ab4=851
⇒100a+10b+1+3·100+10b+a+100a+10b+4=851
⇒201a+30b+300+1+4=851
⇒201a+30b+305=851
⇒201a+30b=851-305
⇒201a+30b=546;⇒nu exista nicio solutie naturala pentru a respecta cerintele;
⇒ab[in baza zece]∉N;