Fie a, b, c să fie aceste nr.
(a+b)/2=9.1 => a+b=18.2
(b+c)/2=19.8 => b+c=39.6
(a+c)/2=13.4 => a+c=26.8
a+b+c=2(a+b+c)/2=((a+b)+(b+c)+(a+c))/2=(18.2 +39.6 +26.8)/2=84.6/2=42.3
a=(a+b+c)-(b+c)=42.3-39.6=2.7
b=(a+b+c)-(a+c)=42.3-26.8=15.5
c=(a+b+c)-(a+b)=42.3-18.2=24.1
