$($a$)$ Use differentiation to find a power series representation for

$f(x)=\frac{1}{(5+x{)}^2}$

$f(x)={\displaystyle \underset{n=0}{\overset{}{}}}()$

What is the radius of convergence, $R?$

$R=$

$($b$)$ Use part $($a$)$ to find a power series for

$f(x)=\frac{1}{(5+x{)}^3}.$

$f(x)={\displaystyle \underset{n=0}{\overset{}{}}}$

What is the radius of convergence, $R?$

$R=$

$($c$)$ Use part $($b$)$ to find a power series for

What is the radius of convergence, $R?$

$R=$