Respuesta :
Answer:
x = ±2
x = ±i
Step-by-step explanation:
(x^2+4)^2 – 11(x^2+4) + 24 = 0
Let m = x^2 +4
(m)^2 – 11(m) + 24 = 0
Solving this quadratic
What two numbers multiply to 24 and add to -11
-8*-3 =24
-8-3 = -11
(m-8)(m-3) =0
m = 8 m=3
Now substitute back
x^2 +4 = 8 x^2 +4 = 3
x^2 +4-4 = 8-4 x^2+4-4 = 3-4
x^2 = 4 x^2 = -1
Taking the square root
sqrt(x^2) = sqrt(4) sqrt(x^2) = sqrt(-1)
x = ±2 x = ±i
Answer:
one value of x = 2
Step-by-step explanation:
[tex](x^2 + 4 )^2 - 11(x^2 + 4 ) + 24 = 0\\\\x^4 + 16 + 8x^2 - 11x^2 -44 + 24 = 0\\\\x^4 - 3x^2 -4 = 0\\\\[/tex] ------ ( 1 )
[tex]Let \ x^2 \ = \ u[/tex]
( 1 ) => [tex]u^2 - 3u - 4 = 0[/tex]
[tex]u^2 -4u + u - 4 = 0\\\\u(u - 4) + 1 (u - 4) = 0\\\\(u + 1) (u - 4) = 0\\\\u = -1 \ , \ u = 4[/tex]
[tex]=> x^2 = - 1 \ and \ x^2 = 4[/tex]
[tex]x = \sqrt {-1} = i[/tex]
[tex]x = \sqrt{4} = \pm 2[/tex]