a+b+c=684
a+b=420
b+c=448
inlocuim ecuatia a 2 a in prima ecuatie si rezulta 420+c=684 rezulta c=684-420 deci c=264
dar b+c= 448 deci b= 448-264 =174 deci b=174
a+b= 420 deci a=420 - b= 420-174=246
a = 246, b = 174 si c = 264
verificare
a+b+c=684
246+174+264=684
684=684 deci se verifica
tot cam la fel
a+b+c=684
a+b=420
b+c=448
420+C=684
c=684-420 deci c=264
b+c=448
b+264=448 deci b=448-264 deci
b=174
a=420-b=420-174 deci
a= 246
