Question

3x² * (x² – 5) = 5 – x²

Answer 1

3x² * (x² - 5) = 5 - x²

3x^4 - 15x² - 5 + x² = 0

3x^4 - 14x² - 5 = 0

3y² - 14y - 5 = 0

delta

d² = (-14)² - 4*3*(-5) = 256

d = 16

y1 = (14 + 16)/6 = 5 --> x1 = +√5, x2 = -√5

y2 = (14 - 16)/6 = -1/3 (raízes complexas)