Question

Abc-cba=se divide la 9,11

Answer 1

Răspuns:

abc-cba=(100*a+10*b+c)-(100*c+10*b+a)=100*a+10*b+c-100*c-10*b-a=99*a-99*c=99*(a-c)=9*11*(a-c) deci numarul se divide cu 9 si 11