Final answer:
When factoring a trinomial, you can factor out -1 when the coefficient of x is negative.
Step-by-step explanation:
When factoring a trinomial, you can factor out -1 when the coefficient of x is negative. This means that you can take out -1 as a common factor from each term of the trinomial. For example, if you have the trinomial -x² - 3x - 2, you can factor out -1 to get -1(x² + 3x + 2).
Learn more about Factoring trinomials