Question

Решите пожалуйста очень срочно!!! ​

Answer 1

Ответ:

$( \frac{a + 4}{a - 4} - \frac{a - 4}{a + 4} ) \div \frac{48a}{16 - {a}^{2} } = ( \frac{ {(a + 4)}^{2} - {(a - 4)}^{2} }{(a - 4)(a + 4)} ) \times \frac{16 - {a}^{2} }{48a} = ( \frac{ {a}^{2} + 8a + 16 - {a }^{2} + 8a - 16 }{(a - 4)(a + 4)} ) \times \frac{16 - {a}^{2} }{48a} = \frac{16a}{(a - 4)(a + 4)} \times \frac{(4 - a)(4 + a)}{48a} = - \frac{ 1}{3}$

$( \frac{ {a}^{2} }{a + 5} - \frac{ {a}^{3} }{ {a}^{2} + 10a + 25} ) \div ( \frac{a}{a + 5} - \frac{ {a}^{2} }{ {a}^{2} - 25 } ) = \frac{5a - {a}^{2} }{a + 5} \\ ( \frac{ {a}^{2} }{a + 5} - \frac{ {a}^{3} }{(a + 5)^{2} } ) \div ( \frac{a}{a + 5} - \frac{ {a}^{2} }{(a - 5)(a + 5)} ) = \frac{5a - {a}^{2} }{a + 5} \\ ( \frac{ {a}^{2}(a + 5) - {a}^{3} }{ {(a + 5)}^{2} } ) \div ( \frac{a(a - 5) - {a}^{2} }{(a - 5)(a + 5)} ) = \frac{5a - {a}^{2} }{a + 5} \\ ( \frac{ {a}^{3} + 5 {a}^{2} - {a}^{3} }{ {(a + 5)}^{2} } ) \div ( \frac{ {a}^{2} - 5a - {a}^{2} }{(a - 5)(a + 5)} ) = \frac{5a - {a}^{2} }{a + 5} \\ \frac{5 {a}^{2} }{ {(a + 5)}^{2} } \div ( - \frac{5a}{(a - 5)(a + 5)} ) = \frac{5a - {a}^{2} }{a + 5} \\ - \frac{5 {a}^{2} }{ {(a + 5)}^{2} } \times \frac{(a - 5)(a + 5)}{5a} = \frac{5a - {a}^{2} }{a + 5} \\ - \frac{a(a - 5)}{(a + 5)} = \frac{5a - {a}^{2} }{a + 5} \\ - \frac{a(a - 5)}{a + 5} = - \frac{a(a - 5)}{a + 5}$