Question

Помогите решить, срочно
x⁴-4x²-5=0

Answer 1

${x}^{2} = t \ {t}^{2} - 4t - 5 = 0 \ d = sqrt{16 + 26} = sqrt{36} = 6 \ t1 = frac{4 + 6}{2} = 5 \ t2 = frac{4 - 6}{2} = - 1$

Answer 2

x⁴-4x²-5=0
х²= а
х⁴= а²
а²-4а-5=0
 a= 1, b= -4, c = -5
D=b²-4ac=  (-4)²-4*1*(-5)=16+20=36
D>0, √D=6
a₁,₂= -b±√D ÷(дробь) 2a= 4±6 ÷(дробь) 2 = 5 и -1
a₁ = 5
a₂=-1