ABC+495 = CBA
CBA-ABC = 495
100C+10B+A -100A-10B-C = 495
99C-99A = 495
99(C-A) = 495
C-A = 495:99
C-A = 5
9-4 = 5
8-3 = 5
7-2 = 5
6-1 = 5
=> A = 4; 3; 2; 1
C = 9; 8; 7; 6
B = 1; 2 ; 3 ; 4
ABC = 419; 328; 237;146.
Verificare:
914-419 = 495
823-328 = 495
732-237 = 495
641-146 = 495
Sunt 4 numere de forma ABC
