somebody pls help with no. 5

Answer:
a) is -7
Step-by-step explanation:
8=2048[tex](2)^{n-1}[/tex]
[tex]\frac{8}{2048} =\frac{2048^{n-1} }{2048}[/tex]
8/2048=0.00390625 = [tex](2)^{n-1}[/tex]
[tex]2^{-8}[/tex] = 0.00390625
-8-1=-7
and do the rest with the same equation which is tn=a[tex]r^{n-1}[/tex]