Question

Insira 10 meios aritméticos entre 3 e 80

Answer 1

a1 = 3
an = 80
n = 12
r = ?

an = a1 + (n-1).r
80 = 3 + (12-1).r
80 - 3 = 11r
77 = 11r
r = 77/11
r = 7

P.A (3, 10, 17, 24, 31, 38, 45, 52, 59, 66, 73, 80)