Question

Encontre o termo geral da P.A. (3, 6, 9)

Answer 1

an = ?     a1 = 3       r = 6 - 3 = 3

an = a1 + (n - 1) . r
an = 3 + (n - 1). 3
an = 3 + 3n - 3
an = 3 - 3 + 3n 
an = 3n