[tex] \frac{1}{5} + { \frac{1}{5} }^{2} + { \frac{1}{5} }^{3} = \\ \\ \\ \frac{1}{5} + \frac{ {1}^{2} }{ {5}^{2} } + \frac{ {1}^{3} }{ {5}^{3} } = \\ \\ \\ \frac{1}{5}^{ \times 25} + \frac{1}{25}^{ \times 5}+ \frac{1}{125} = \\ \\ \\ \frac{25}{125} + \frac{5}{125} + \frac{1}{125} = \\ \\ \\ \frac{31}{125} [/tex]
