Factor $LaTeX: \displaystyle - 28 x^{3} - 63 x^{2} + 40 x + 90$ .

Factoring out the GCF $LaTeX: \displaystyle -1$ from each term gives $LaTeX: \displaystyle -(28 x^{3} + 63 x^{2} - 40 x - 90)$ . Grouping the first two terms and factoring out their GCF, $LaTeX: \displaystyle 7 x^{2}$ , gives $LaTeX: \displaystyle 7 x^{2}(4 x + 9)$ . Grouping the last two terms and factoring out their GCF, $LaTeX: \displaystyle -10$ , gives $LaTeX: \displaystyle -10(4 x + 9)$ . The polynomial now has a common binomial factor of $LaTeX: \displaystyle 4 x + 9$ . This gives $LaTeX: \displaystyle -1[7 x^{2} \left(4 x + 9\right) -10 \cdot \left(4 x + 9\right)] = -\left(4 x + 9\right) \left(7 x^{2} - 10\right)$ .