Răspuns :
a+b=150
a-b=30 => a = 30+b
30+b + b = 150
2b=120
b = 60 => a = 30+b = 30+60 => a = 90
a-b=30 => a = 30+b
30+b + b = 150
2b=120
b = 60 => a = 30+b = 30+60 => a = 90