Solve $LaTeX: \displaystyle - 5 x^{2} - 80 x - 300=0$

Since the GCF is $LaTeX: \displaystyle -5$ we need we factor out the GCF to get $LaTeX: \displaystyle -5(x^{2} + 16 x + 60)$ . This is now a pq method factoring. The factors of $LaTeX: \displaystyle 60$ that add up to $LaTeX: \displaystyle 16$ are $LaTeX: \displaystyle 6$ and $LaTeX: \displaystyle 10$ . This gives $LaTeX: \displaystyle -5(x + 6)(x + 10)=0$ . The solutions are $LaTeX: \displaystyle x = -6$ and $LaTeX: \displaystyle x = -10$