Răspuns :
a+b+c=408
a-2=b:4...=> b=(a-2)*4...=> b=4a-8
c=(a+b):2....=> a+b=2c
inlocuim in relatie..=> 2c+c=408
3c=408
c=408:3
c=136
a+b+136=408
a+b=408-136
a+b=272
inlocuim in relatie...=> a+4a-8=272
5a-8=272
5a=272+8
5a=280
a=280:5
a=56
b=56*4-8
b=224-8
b=216
56+216+136=
=272+136
=408
verificare
56-2=216:4
54=54
136=(56+216):2
136=272:2
136=136
a-2=b:4...=> b=(a-2)*4...=> b=4a-8
c=(a+b):2....=> a+b=2c
inlocuim in relatie..=> 2c+c=408
3c=408
c=408:3
c=136
a+b+136=408
a+b=408-136
a+b=272
inlocuim in relatie...=> a+4a-8=272
5a-8=272
5a=272+8
5a=280
a=280:5
a=56
b=56*4-8
b=224-8
b=216
56+216+136=
=272+136
=408
verificare
56-2=216:4
54=54
136=(56+216):2
136=272:2
136=136