Expanding the left side of the equation, we get:
(х^2 + х - 4)(х^2 + х + 4) = x^4 + x^3 + 4x^2 + x^3 + x^2 + 4x - 4x^2 - 4x - 16= x^4 + 2x^3 + x^2 - 16
Set this equal to 9:
x^4 + 2x^3 + x^2 - 16 = 9
Rearranging the terms, we get:
x^4 + 2x^3 + x^2 - 25 = 0
This is our final equation.
Expanding the left side of the equation, we get:
(х^2 + х - 4)(х^2 + х + 4) = x^4 + x^3 + 4x^2 + x^3 + x^2 + 4x - 4x^2 - 4x - 16
= x^4 + 2x^3 + x^2 - 16
Set this equal to 9:
x^4 + 2x^3 + x^2 - 16 = 9
Rearranging the terms, we get:
x^4 + 2x^3 + x^2 - 25 = 0
This is our final equation.