Respuesta :

devishri1977

Answer:

Step-by-step explanation:

Geometric sequence: 9, -18 , 36 .....

common ratio = 2nd term / 1st term

                      = -18 /9 = -2

[tex]a_{n}=ar^{n-1}\\\\a_{9}=9*(-2)^{8}\\\\=9*256\\\\= 2304[/tex]