Final answer:
The key difference is that the bolded trinomial, 2x² + 5x + 1, has a leading coefficient of 2, whereas the trinomial x² + 5x + 6 has a leading coefficient of 1.
Step-by-step explanation:
The difference between the trinomials 2x² + 5x + 1 and x² + 5x + 6 is in their leading coefficients. The bolded trinomial, 2x² + 5x + 1, has a leading coefficient of 2, which means that the x² term is multiplied by 2. In contrast, the trinomial x² + 5x + 6 has a leading coefficient of 1. This affects how they are factored; with the bolded trinomial, you'll need to consider the product of the leading coefficient and the constant term when finding factors that sum to the middle coefficient.