Răspuns :
a+b+c=800
a+b=600
b+c=540
inlocuim necunoscutele:
600+c=800
c=800-600
c=200
b+200=540
b=540-200
b=340
a+340+200=800
a+540=800
a=800-540
a=260
proba:
260+340+200=800
a+b=600
b+c=540
inlocuim necunoscutele:
600+c=800
c=800-600
c=200
b+200=540
b=540-200
b=340
a+340+200=800
a+540=800
a=800-540
a=260
proba:
260+340+200=800