CPM Homework Help : INT3 Problem 12-82

What is the sum (if possible) for each of the following infinite series?

$8-6+\frac{9}{2}-\frac{27}{8}+...$
Hint (a):
$r=\frac{-6}{8}$
Hint 2(a):
$s=\frac{a}{1-r}$

$\quad \displaystyle\sum _ { k = 0 } ^ { \infty } \frac { 1 } { 8 } ( 2 ) ^ { k }$
Hint (b):
$r = 2$
so not possible.