Răspuns :
(a+b+c):3=18,03
a+b+c=54,09
(a+b):2=15,94
a+b=31,88
a+b+c=54,09
31,88+c=54,09
c=22,21
a+b+c=54,09
(a+b):2=15,94
a+b=31,88
a+b+c=54,09
31,88+c=54,09
c=22,21