Respuesta :

[tex]{( \frac{2}{5 {n}^{9} } ) }^{2} = \frac{ {2}^{2} }{( {5 {n}^{9} )}^{2} } = \frac{4}{ {5}^{2} {n}^{9 \times 2} } = \frac{4}{25 {n}^{18} } [/tex]