Răspuns :
5750-5111=639
639:3=213
213-3=210
Verificam:210+3 =213
213x3=639
639+5111=5750
639:3=213
213-3=210
Verificam:210+3 =213
213x3=639
639+5111=5750
(x+3ori 3)+5111=5750
x+9+5111=5750
x+5120=5750
x=5750-5120
x=630
PROBA:
(630+3ori3)+5111=5750
630+9+5111=5750
NR=630
x+9+5111=5750
x+5120=5750
x=5750-5120
x=630
PROBA:
(630+3ori3)+5111=5750
630+9+5111=5750
NR=630