Answer:
-8(x^2 - 1)
Explanation:
(x^2 + 3)^2 and (x^2 - 1)^2 are both squares of binomials. The first step here is to expand both:
-(x^2 + 3)^2 = -x^4 - 6x^2 - 9
(x^2 - 1)^2 = x^4 - 2x^2 + 1
Combine the two right-hand expressions, obtaining:
-8x^2 - 8 or -8(x^2 - 1)
This -8(x^2 - 1) is the simplest form of the given expression.
If desired, -8(x^2 - 1) can be factored: -8(x - 1)(x + 1)