/ / 4 2\
| 2 | (-5 + x) 4*(-5 + x) |
| (-5 + x) *|1 + --------- + -----------| | 2|
| \ 81 9 / |(-5 + x) |
|------------------------------------------------ for ----------- < 1
| 2 9
| / 2\ / 2 4\
| | (-5 + x) | | 2*(-5 + x) (-5 + x) |
|9*|1 - ---------| *|1 - ----------- + ---------|
< \ 9 / \ 9 81 /
|
| oo
| ___
| \ `
| \ -n 3 2*n
| / 9 *n *(-5 + x) otherwise
| /__,
| n = 1
\
----------------------------------------------------------------------
-5 + x
$$\frac{\begin{cases} \frac{\left(x - 5\right)^{2} \left(\frac{\left(x - 5\right)^{4}}{81} + \frac{4 \left(x - 5\right)^{2}}{9} + 1\right)}{9 \left(1 - \frac{\left(x - 5\right)^{2}}{9}\right)^{2} \left(\frac{\left(x - 5\right)^{4}}{81} - \frac{2 \left(x - 5\right)^{2}}{9} + 1\right)} & \text{for}\: \frac{\left|{\left(x - 5\right)^{2}}\right|}{9} < 1 \\\sum_{n=1}^{\infty} 9^{- n} n^{3} \left(x - 5\right)^{2 n} & \text{otherwise} \end{cases}}{x - 5}$$
Piecewise(((-5 + x)^2*(1 + (-5 + x)^4/81 + 4*(-5 + x)^2/9)/(9*(1 - (-5 + x)^2/9)^2*(1 - 2*(-5 + x)^2/9 + (-5 + x)^4/81)), Abs((-5 + x)^2)/9 < 1), (Sum(9^(-n)*n^3*(-5 + x)^(2*n), (n, 1, oo)), True))/(-5 + x)