Question

quantos termos tem a PG
(2,6,18,....,4374)

Answer 1

q = 6/2 = 3

an = a1 . q ^n - 1

4374 = 2 . 3 ^n - 1

fatorando 4374 = 2 . 3 elevado a 7

2 . 3elevado a 7 = 2 .3 ^n - 1 cortando as bases 2 e 3

n - 1 = 7

n = 7 +1

n = 8