Question

3) Encontre o termo geral da P.A. (12, 16, 20,...).​

Answer 1

a1 = 12

r = 16 - 12 = 4

an = a1 + (n - 1).r

an = 12 + (n - 1).4

an = 12 + 4n - 4

an = 4n + 8

an = 4(n + 2)

Resposta: an = 4(n + 2)