Question

Find the 12 term of the geometric sequence 9,-18,36,...

Answer 1

Answer:

$a = 9$

$r = \frac{-18}{9}$

$r = -2$

$a_{12} = 9×(-2)^{(12-1)}$

$a_{12} = 9×(-2)^{11}$

$a_{12} = 9×(-2048)$

$a_{12} = -18432$

Answer 2

Step-by-step explanation:

a=9 d= -18-9= -27

a12= a+11d

    9+11*-27

=9+-297

= -288

hope it helps