Răspunsuri

2014-04-22T19:14:37+03:00
10a+b-9=a+b,a=1,b=orice cifra
numrele de o cifra nu pot indeplini aceasta conditie,ci doar nr de doua cifre.
Aceasta conditie o pot indeplini 10 nr
2014-04-22T19:24:36+03:00

 10c_{1} + c_{2} - 9 = c _{1} + c_{2}  
numerele <20 =>  c_{1} =1 fara numerele <10
 c_{2} =1,2,3,4,5,6,7,8,9;

Sunt 10 numere: 10,11,12,13,14,15,16,17,18,19;