Răspuns :
Răspuns:
(a+a+1+a+2)/3=21
(3a+3)=21·3
3a=63-3
a=60:3=>a=20
20+1=21
20+2=22
nr consecutive sunt: 20,21,22
Trei numere naturale consecutive se pot scrie : a-1, a, a+1
[tex]\it m_a=\dfrac{a-1+a+a+1}{3}=21 \Rightarrow \dfrac{3a}{3}=21 \Rightarrow a=21[/tex]
Numerele cerute sunt: 20, 21, 22