Răspuns :
a+b=129
a-b=41
---------------
2a=170
a=85
85+b=129
b=129-85
b=44
proba:
85+44=129
85-44=41
a-b=41
---------------
2a=170
a=85
85+b=129
b=129-85
b=44
proba:
85+44=129
85-44=41