Question

[tex]x^{4} -13 x^{2} +36=0

Answer 1

$x^{4}-13x^{2}+36=0\ x^{2}=t\ t^{2}-13t+36=0\ t_{1}=9\ t_{2}=4\ x^{2}=9\ x=3;x=-3;\ x^{2}=4\ x=2;x=-2;$

Ответ: -2, 2, -3, 3.