(x - 2)³ + (x + 2)³ = 2(x - 3) (x² + 3x + 9)
х³ - 3х²у + 3ху² - у³
х³ - 6х² + 12х - 8 = 2 ( х³ + 3х² + 9х - 3х² - 9х - 6)
х³ - 6х² + 12х - 8 = 2х³ - 12
х³ - 2х³ - 6х² + 12х = -12 + 8
-х³ - 6х² + 12х = -4
-х(х² + 6х - 12) = -4
х₁ = 4 х² + 6х - 12 = -4
х² + 6х = -4 + 12
х² + 6х = 8
х(х + 6) = 8
х₂ = 8 х₃ = 2
