CPM Homework Help : CALC Problem 12-105

$f(x) =\frac { 4 } { 1 - 2 x }$
Step 1(a):
$f(x)=4\Big(\frac{1}{1-(2x)}\Big)$
Step 2(a):
$p(x)=4(1+(2x)+(2x)^2+(2x)^3+...)$
Step 3(a):
$p(x)=4\displaystyle\sum_{n=0}^\infty (2x)^n$
Step 4(a):
$\lim\limits_{n\to\infty}\Big|\frac{2^{n+1}x^{n+1}}{2^nx^n}\Big|$
Step 5(a):
$2|x|<1$

$g(x) =\frac { 6 } { x + 5 }$
Step 1(b):
$g(x)=6\Big(\frac{1}{5(1-(-x/5))}\Big)$
Step 2(b):
$g(x)=\frac{6}{5}\Big(\frac{1}{1-(-x/5)}\Big)$
More Help (b):
Now follow the steps outlined in part (a).

$h(x) =\frac { 3 } { 2 x + 7 }$
Step 1(c):
$h(x)=3\Big(\frac{1}{7(1-(-2x/7)}\Big)$
More Help (c):
Now follow the steps outlined in parts (b) and (c).