Question

Media aritmetica a 3 numere naturale este 20. Aflati numerele stiind ca primele doua au media aritmetica 19iar ultimele doua au media aritmetica 21
Multumesc anticipat

Answer 1

(a+b+c)/3=20
a+b)/2=19..a+b=19x2=38
(b+c)/2=21...b+c=21x2=42
(38+c)/3=20  38+c=20x3 c=60-38=22
b+c=42
c=22 atunci b=42-22=20
(a+20+22)/3=20
a+20+22=60
aa=60-42
a=18

Answer 2

a+b+c/3=20,deci a+b+c=60 a+b/2=19,deci a+b=38 b+c/2=21,deci b+c=42 Stiind ca a+b =38,inlocuim in prima ecuatie ,deci 38+c= 60=> c=22 Stim ca b+c= 42 si c = 22,inlocuim b+22=42 => b=20. a+b = 38 si b =20,inlocuim si => a =38-20=18. A= 18,B= 20,C= 22.. 18+20+22=60..