Question

Afla trei nr.nat.consecutive știind că media lor este 78

Answer 1

a,b,c-nr nat . consecutive
(a+b+c):3=78=>a+b+c=78×3=234
b=a+1
c=a+2
______
a,b,c=?
______
a+a+1+a+2=234
3a=231
a=231:3
a=77
b=71+1
b=78
c=78+1
c=79

Answer 2

media aritmetica=(a+b+c):3⇒(a+a+1+a+2):3=78
3a+3=78*3
3a+3=234
3a=234-3
3a=231
a=77
Numerele sunt:77,78 si 79.