Question

x4 + 5x² - 36 = 0;
Поомомомомоммогиттетееее

Answer 1

х⁴ + 5х² - 36 = 0

х² = t

x⁴ = t²

t² + 5t - 36 = 0

D = b³ - 4ac = 5² - 4 × 1 × (-36) = 25 + 144 = 169

√D = √169 = 13

x1 = (- b + √D)/2a = (- 5 + 13)/2 = 4

x2 = (- b - √D)/2a = (- 5 - 13)/2 = - 9

Ответ: х1 = 4, х2 = - 9