1) a+b+c+d=9992 ⇒d=9992-7153 ⇒d=2839a+b+c=7153 ⇒c=7153-3586⇒c=3567
a+b=3586 ⇒a+2347=3586⇒a=3586-2347⇒a=1239
b=c-1220 ⇒b=3567-1220⇒b=2347
2) a+b+c=8257 ⇒c=8257-6276⇒c=1981
a+b=6276 Daca b =362 ⇒a+362=6276⇒a=6276-362⇒a=5914
c=b+1619 ⇒Daca c=1981⇒1981=b+1619⇒b=1981-1619⇒b=362