a + b + c = 287
a = 1/2 x b + 12
c = 25 + b
Inlocuim in relatie
1/2 x b + 12 + b + 25 + b = 287
b/2 + 2b + 37 = 287
b/2 + 2b = 250
amplificam cu 2 fiecare
b/2 + 4b/2 = 520/2 l inmultim totul cu 2
b + 4b = 500
5b = 500
b = 100
a = 100/2 + 12 = 62
c = 100 + 25 = 125
a+b+c = 62 + 100 + 125 = 162 + 125 = 287
TI-AM CORECTAT