Respuesta :

ghanami

Answer:

Step-by-step explanation:

hello :

the sequence 9,-18,36 is geometric when the common ratio is:

r= 36/-18=-18/9=-2

let (An) this sequence the n-ieme term is : An=A1×r^(n-1).....A1=9 and n=9

A9=9×(-2)^8 =2304