Introductory Algebra for College Students (7th Edition)

$$-2x^4 + 3x^2 - 1$$
Looking at the numerator of this problem, we see that we can first factor out a $4x^2$ from each of the terms. We rewrite the problem with the $4x^2$ factored out: $$\frac{4x^2(-2x^4 - 3x^2 - 1)}{4x^2}$$ We can cancel out the $4x^2$ term from both the numerator and denominator: $$-2x^4 + 3x^2 - 1$$