Factor $LaTeX: \displaystyle - 32 x^{3} - 72 x^{2} - 40 x - 90$ .

Factoring out the GCF $LaTeX: \displaystyle -2$ from each term gives $LaTeX: \displaystyle -2(16 x^{3} + 36 x^{2} + 20 x + 45)$ . Grouping the first two terms and factoring out their GCF, $LaTeX: \displaystyle 4 x^{2}$ , gives $LaTeX: \displaystyle 4 x^{2}(4 x + 9)$ . Grouping the last two terms and factoring out their GCF, $LaTeX: \displaystyle 5$ , gives $LaTeX: \displaystyle 5(4 x + 9)$ . The polynomial now has a common binomial factor of $LaTeX: \displaystyle 4 x + 9$ . This gives $LaTeX: \displaystyle -2[4 x^{2} \left(4 x + 9\right) +5 \cdot \left(4 x + 9\right)] = -2\left(4 x + 9\right) \left(4 x^{2} + 5\right)$ .