Помогите пж ааа ну давай

Ответ : 5).
$\frac{1}{u + p} + \frac{3up}{ {u}^{3} + {p}^{3} } = \frac{1}{u + p} + \frac{3up}{(u + p)( {u}^{2} - pu + {p}^{2} ) } = \frac{ {u}^{2} - pu + {p}^{2} + 3pu}{(u + p)( {u}^{2} - pu + {p}^{2} ) } = \frac{ {u}^{2} + 2pu + {p}^{2} }{(u + p)( {u}^{2} - pu + {p}^{2} )} = \frac{ {(u + p)}^{2} }{(u + p)( {u}^{2} - pu + {p}^{2} )} = \frac{u + p}{ {u}^{2} - pu + {p}^{2} }$