Răspunsuri

2014-02-26T17:30:52+02:00
  • Utilizator Brainly
2014-02-26T18:03:02+02:00
E vorba de un numar de doua cifre, ele au forma ab (cu bara deasupra).
ab=10a+b=a+b+9 ⇒ 9a=9 ⇒ a=1, b oricare;
vom avea 10=9+1; 11=9+2; 12=9+3, 13=9+4; 14=9+5; 15=9+6, 16=9+7; 17=9+8; 18=9+9.
Solutia: (a,b) ∈ {(1,0);(1,1);(1,2);(1,3);(1,4);(1,5);(1,6);(1,7);(1,8)}.
1 5 1