Question

Media aritmetică a trei numere naturale consecutive este 21. Aflați numerele.

Ajutati-ma va rog frumos

Answer 1

$\frac{x+y+z}{3}=21 \\ x+y+z=21 \cdot 3=63 \\ y=x+1 \\ z=y+1=x+2 \\ x+x+1+x+2=63 \\ 3x+3=63 \\ 3x=63-3=60 \\ x=\frac{60}{3} \\ \boxed{\bold{x=20}} \\ y=x+1=20+1 \\ \boxed{\bold{y=21}} \\ z=y+1=21+1 \\ \boxed{\bold{z=22}}$

Answer 2

(x+x+1+x+2):3=21
3x+3=21×3
3x=63-3
x=60:3
x=20
nr sunt:20,21,22