Factor $LaTeX: \displaystyle - 15 x^{3} - 24 x^{2} - 50 x - 80$ .

Factoring out the GCF $LaTeX: \displaystyle -1$ from each term gives $LaTeX: \displaystyle -(15 x^{3} + 24 x^{2} + 50 x + 80)$ . Grouping the first two terms and factoring out their GCF, $LaTeX: \displaystyle 3 x^{2}$ , gives $LaTeX: \displaystyle 3 x^{2}(5 x + 8)$ . Grouping the last two terms and factoring out their GCF, $LaTeX: \displaystyle 10$ , gives $LaTeX: \displaystyle 10(5 x + 8)$ . The polynomial now has a common binomial factor of $LaTeX: \displaystyle 5 x + 8$ . This gives $LaTeX: \displaystyle -1[3 x^{2} \left(5 x + 8\right) +10 \cdot \left(5 x + 8\right)] = -\left(5 x + 8\right) \left(3 x^{2} + 10\right)$ .