Respuesta :
Answer:
Option (2)
Step-by-step explanation:
Given equation is,
x⁴- 9x² + 8 = 0
Let x² = t
By substituting the value of x²= t in the equation,
t² - 9t + 8 = 0
t² - 8t - t + 8 = 0
t(t - 8) - 1(t - 8) = 0
(t - 1)(t - 8) = 0
(t - 1) = 0 ⇒ t = 1
(t - 8) = 0 ⇒ t = 8
Since, t = x²
x² = 1 ⇒ x = ±1
x² = 8 ⇒ x = ±2√2
Therefore, Option (2) will be the correct option.