Question

Help me solve the second problem.

Answer 1

$\frac{x + \frac{1}{x} }{x - \frac{1}{x} } = 3$
$\frac{ \frac{ {x}^{2} + 1 }{x} }{ \frac{ {x}^{2} - 1 }{x} } = 3$
$\frac{ {x}^{2} + 1 }{ {x}^{2} - 1 } = 3$
${x}^{2} + 1 = 3 {x}^{2} - 3$
$2 {x}^{2} - 4 = 0$
${x}^{2} - 2 = 0$
${x}^{2} = 2$
$x = \sqrt{2}$