Question

Помогите решить, пожалуйста!!!!

Answer 1

$\frac{1}{3 \sqrt{2} - 4 } - \frac{1}{3 \sqrt{2} + 4 } = \frac{3 \sqrt{2} + 4 - (3 \sqrt{2} - 4)}{ (3 \sqrt{2} + 4)(3 \sqrt{2} - 4)} = \frac{3 \sqrt{2} + 4 - 3 \sqrt{2} + 4}{{3}^{2} \times 2 - {4}^{2} } = \frac{8}{2} = 4$
$( \frac{x + 3}{ {x}^{2} - 3x } + \frac{x - 3}{ {x}^{2} + 3x} ) \times \frac{9x - {x}^{3} }{ {x}^{2} + 9} = ( \frac{(x + 3)(x + 3) + (x - 3)(x - 3) }{x(x - 3)(x + 3)} ) \times \frac {x(9 - {x}^{2} )}{ {x}^{2} + 9 } = \frac{ {x}^{2} + 6x + 9 + {x}^{2} - 6x - 9}{x( {x}^{2} - 9)} \times \frac {( - x)({x}^{2} - 9 )}{ {x}^{2} + 9 } = \frac{ - 2 {x}^{2} }{ {x}^{2} + 9}$