Question

Determine o nono termo da pg (-3,-9...) ?

Answer 1

_ Vamos achar a razão.

q =a2/a1
q = 3

_ Achando a9

a9 = a1 . q^8
a9 = -3.(3^8)
a9 = -3.6561
a9= -19683

Answer 2

R = A2 ÷ A1
R = (-9) ÷ (-3)
R = 3

PG = {-3,-9,-27,-81,-243,-729,-2187,-6561,-19683}

$An = A1 * Q^N^-^1$
$A9 = (-3)*3^9^-^1$
$A9 = (-3)*3^8$
$A9 = (-3) * 6561$
$A9 = -19683$

-3 X 3 = 9
-9 X 3 = 27
-27 X 3 = 81
-81 X 3 = 243
-243 X 3 = 729
-729 X 3 = 2187
-2187 X 3 = 6561
-6561 X 3 = 19683

RESPOSTA :

A9 = -19683