Question

(x²+8x+3)*(x²+8x+5)=63. через дискриминант​

Answer 1

(x²+8x+3)*(x²+8x+5)=63

x²+8x+4 = t

(t - 1)(t + 1) = 63

t² - 1 = 63

t² = 64

1. t = 8

x²+8x+4 = 8

x²+8x-4 = 0

D = 64 + 16 = 80

x₁₂ = (-8 +- √80)/2 = -4 +- 2√5

2. t = -8

x²+8x+4 = -8

x²+8x + 12 = 0

D = 64 - 48 = 16

x₁₂ = (-8 +- 4)/2 = -6   -2

Ответ х = {-6, -2, -4 + 2√5, -4 - 2√5}