Chapter 4 Quadratic Functions and Factoring - 4.8 Use the Quadratic Formula and the Discriminant - 4.8 Exercises - Skill Practice - Page 296: 6

$$x=8\pm\sqrt{57}$$

We first check that the function is in the form $ax^2+bx+c$. Then, using the quadratic formula, we obtain: $$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$$ $$x=\frac{16\pm \sqrt{(-16)^2-4(1)(7)}}{2(1)}$$ $$x=8\pm\sqrt{57}$$