Factor $LaTeX: \displaystyle - 90 x^{3} - 70 x^{2} - 27 x - 21$ .

Factoring out the GCF $LaTeX: \displaystyle -1$ from each term gives $LaTeX: \displaystyle -(90 x^{3} + 70 x^{2} + 27 x + 21)$ . Grouping the first two terms and factoring out their GCF, $LaTeX: \displaystyle 10 x^{2}$ , gives $LaTeX: \displaystyle 10 x^{2}(9 x + 7)$ . Grouping the last two terms and factoring out their GCF, $LaTeX: \displaystyle 3$ , gives $LaTeX: \displaystyle 3(9 x + 7)$ . The polynomial now has a common binomial factor of $LaTeX: \displaystyle 9 x + 7$ . This gives $LaTeX: \displaystyle -1[10 x^{2} \left(9 x + 7\right) +3 \cdot \left(9 x + 7\right)] = -\left(9 x + 7\right) \left(10 x^{2} + 3\right)$ .