Solve $LaTeX: \displaystyle - 5 x^{2} + 15 x + 350=0$

Since the GCF is $LaTeX: \displaystyle -5$ we need we factor out the GCF to get $LaTeX: \displaystyle -5(x^{2} - 3 x - 70)$ . This is now a pq method factoring. The factors of $LaTeX: \displaystyle -70$ that add up to $LaTeX: \displaystyle -3$ are $LaTeX: \displaystyle -10$ and $LaTeX: \displaystyle 7$ . This gives $LaTeX: \displaystyle -5(x - 10)(x + 7)=0$ . The solutions are $LaTeX: \displaystyle x = 10$ and $LaTeX: \displaystyle x = -7$