Question

Срочно помогите пожалуйста​

Answer 1

Ответ:

$\frac{8 {a}^{2} }{ {a}^{3} - 1 } + \frac{a + 1}{ {a}^{2} + a + 1} = \frac{ {8a}^{2} + (a -1 )(a + 1) }{(a -1 )( {a }^{2} + a + 1)} = \frac{8 {a}^{2} + {a}^{2} + a - a - 1 }{ {a}^{ 3} - 1 } = \frac{9 {a}^{2} - 1 }{ {a}^{3} - 1} = \frac{9 \times {2}^{2} - 1}{ {2}^{3} - 1} = \frac{9 \times 4 - 1}{8 - 1} = \frac{36 - 1}{7} = \frac{35}{7} = 5$