Răspuns :
a + b = 393
a : b = 15 (rest 9) => a = 15b+9
↓
15b+9 + b = 393
16b = 384
b = 24
↓
a = 369 si b = 24
a : b = 15 (rest 9) => a = 15b+9
↓
15b+9 + b = 393
16b = 384
b = 24
↓
a = 369 si b = 24