a + b + c = 167
a + b - c = 67
____________ → scad relatiile
/ ...../ 2 c = 100
c = 100 : 2
c = 50
_____________
a + b = 67 + 50
a + b = 117
b + c - a = 37
b + 50 = a + 37 ⇒ b = a + 37 - 50 ⇒ b = a - 13 ⇔ a = b + 13
_____________________________________________
a + b = 117
b + 13 + b = 117
2 x b = 117 - 13
b = 104 : 2 ⇒ b = 52
a = 52 + 13 ⇒ a = 65
__________________
Verific: a + b + c = 65 + 52 + 50 = 167
b + c - a = 52 + 50 - 65 = 102 - 65 = 37
