Răspunsuri

2014-11-08T15:52:32+02:00
N=111a-100a - 11b +3b-3a = 8a -8b = 8(a-b) care este patrat perfect daca a-b=8*.
k≥2 imposibil
k=1 => a-b=8 => a=9 si b=1.
k=0 => a-b=0 => a=b={1,2,3...9}
Solutie: (a,b) ∈ {(9,1); (1,1) ; (2,2) ;(3,3)...;(9,9)}