Question

$x+ \frac{1}{x}=3$
$x^{2}+ \frac{1}{ x^{2} }$=?

Answer 1

ridicata la patrat => $x^{2} + \frac{1}{ x^{2} } +2 = 9$ =>
$x^{2} + \frac{1}{ x^{2} } = 7$