CPM Homework Help : PCT Problem 8-90

Given a geometric sequence with first term $a_{1} = 8$ and common ratio $r = - \frac { 1 } { 2 }$ , write the first $5$ terms of the sequence.

Partial Answer:

$a_1=8$

$a_2=(8)\left(-\frac{1}{2}\right)=-4$

$a_3=(8)\left(-\frac{1}{2}\right)\left(-\frac{1}{2}\right)=$

$a_4=(8)\left(-\frac{1}{2}\right)\left(-\frac{1}{2}\right)\left(-\frac{1}{2}\right)=$