Answer:
x ∈ ( - ∞ , - 8 ) ∪ ( - 8 , 0 ) ∪ ( 0 , 8 ) ∪ ( 8 , ∞ )
Step-by-step explanation:
x³ - 64x = x( x² - 64 ) ≠ 0 ⇒ x ≠ 0 and x ≠ ± 8
