x + 5 = (x + 5)(x² + 4x + 5)
(x + 5) - (x + 5)(x² + 4x + 5) = 0
(x + 5)(1 - x² - 4x - 5) = 0
(x + 5)(x² + 4x + 4) = 0
(x + 5)(x + 2)² = 0
или x + 5 = 0 или x + 2 = 0
x₁ = - 5 x₂ = - 2
