Răspuns :
a+b+c=100
a+b=69
c=b-2
69+b-2=100
b=100+2-69
b=33
a+33=69
a=69-33
a=36
c=33-2
c=31
verificare
33+36+31=100
a+b=69
c=b-2
69+b-2=100
b=100+2-69
b=33
a+33=69
a=69-33
a=36
c=33-2
c=31
verificare
33+36+31=100
a+b+c=100
a+b=69
c=b-2
69+(b-2)=100/-69
b-2=31/+2
b=33
a=69-33
a=36
c=33-2
c=31
a+b=69
c=b-2
69+(b-2)=100/-69
b-2=31/+2
b=33
a=69-33
a=36
c=33-2
c=31