Can someone help me with these questions

Answer:
The answer is below
Step-by-step explanation:
The nth term of a geometric sequence is given as:
[tex]a_n=ar^{n-1}\\\\where\ a=first\ term,a_n=nth\ term, r=common\ ratio=\frac{a_n}{a_{n-1}}[/tex]
9)
a = -4, r = 12 / -4 = -3
10)
a = -2, r = -8 / -2 = 4
[tex]a_{8}=-2*(4)^{8-1}=-2*(4)^{7}=-32768[/tex]
11)
a = -1, r = -5
[tex]a_{9}=-1*(-5)^{9-1}=-1*(-5)^{8}=-390625[/tex]
12)
a = -1, r = -2
[tex]a_{12}=-1*(-2)^{12-1}=-1*(-2)^{11}=2048[/tex]