Question

Exercițiul 2 punctul b)

Answer 1

$a- \frac{2}{a} =3$
$(a- \frac{2}{a})^2 =3^2$
$a^2-\frac{2*a*2}{a}+ \frac{4}{a^2}=9$
$a^2-4+\frac{4}{a^2}=9$
$a^2+ \frac{4}{a^2}=9+4$
$a^2+ \frac{4}{a^2}=13$