Question

What is the 7th term of the geometric sequence where a1 = -2 and a5 = -512?

Answer 1

\[a5= a1* r^4\\
-512= -2 r^4\\
r=4 \\or \\r=-4
\]

Answer 2

if r=4
\[
a_7=-2 (4)^6=-8192
\]

Answer 3

We obtain the same a7 for r=-4