Respuesta :

Aaqib10

Answer:

x = 1 or -1  

x = -2 or 2

Step-by-step explanation:

x4 - 5x2 + 4 = 0

x4 - 4 x2 - x2 + 4 =0

x2 ( x2 - 4 ) - 1 ( x2 - 4 ) = 0

( x2 - 1 ) ( x2 - 4 ) =

x2 - 1 = 0         or          x2 - 4 = 0

x2 = 1                            x2 = 4

x = 1 or -1                              x = -2 or 2