Factor $LaTeX: \displaystyle - 48 x^{3} - 60 x^{2} - 64 x - 80$ .

Factoring out the GCF $LaTeX: \displaystyle -4$ from each term gives $LaTeX: \displaystyle -4(12 x^{3} + 15 x^{2} + 16 x + 20)$ . Grouping the first two terms and factoring out their GCF, $LaTeX: \displaystyle 3 x^{2}$ , gives $LaTeX: \displaystyle 3 x^{2}(4 x + 5)$ . Grouping the last two terms and factoring out their GCF, $LaTeX: \displaystyle 4$ , gives $LaTeX: \displaystyle 4(4 x + 5)$ . The polynomial now has a common binomial factor of $LaTeX: \displaystyle 4 x + 5$ . This gives $LaTeX: \displaystyle -4[3 x^{2} \left(4 x + 5\right) +4 \cdot \left(4 x + 5\right)] = -4\left(4 x + 5\right) \left(3 x^{2} + 4\right)$ .