Verified answer

(x-1)(х + 1)(х-2)(х + 8) < 0

Метод интервалов

(x-1)(х + 1)(х-2)(х + 8) = 0

x = 1

x = -1

x = 2

x = -8

++++++++++(-8) ------------- (-1) +++++++++ (1) ----------------- (2) ++++++++++

x ∈ (-8, -1) U (1,2)