Răspuns :
a + b + c = 170
a - b = 50 => a = 50 + b
b - c = 30 = > c = b - 30
50 + b + b + b - 30 = 170
3b = 170 - 50 + 30
3b = 150
b = 150 : 3
b = 50
a = 50 + 50 = 100
c = 50 - 30 = 20
100 + 50 + 20 = 170
a - b = 50 => a = 50 + b
b - c = 30 = > c = b - 30
50 + b + b + b - 30 = 170
3b = 170 - 50 + 30
3b = 150
b = 150 : 3
b = 50
a = 50 + 50 = 100
c = 50 - 30 = 20
100 + 50 + 20 = 170