Question

Решите, пожалуйста, уравнение)
х⁴ + 2х³ - 2х - 1 = 0

Answer 1

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Answer 2

$x^4+2x^3-2x-1=(x^2-1)(x^2+1)+2x(x^2-1)=$
$=(x^2-1)(x^2+2x+1)=(x^2-1)(x+1)^2=0 \ \textless \ =\ \textgreater \ x=1, x=-1$