Question

Use the quadratic formula to solve 9x2 + 6x – 17 = 0. A. B. x = –1, –5 C. D.

Answer 1

Answer:

$x_{1} = -\frac{1}{3} +\sqrt{2} ; x_{2} = -\frac{1}{3}-\sqrt{2}$

Step-by-step explanation:

9x² + 6x – 17 = 0

Apply the quadratic formula

$x = \frac{-b\pm\sqrt{b^2-4ac}}{2a}$

a = 9; b = 6; y = -17

$x = \frac{-6\pm\sqrt{6^2 - 4\times 9 \times(-17)}}{2\times 9}$

$x = \frac{-6\pm\sqrt{36+36\times17}}{18}$

$x = \frac{-6\pm\sqrt{36(1+17)}}{18}$

$x = \frac{-6\pm 6 \sqrt{18}}{18}$

$x = \frac{-1\pm \sqrt{9\times2}}{3}$

$x = \frac{-1\pm 3\sqrt{2}}{3}$

$x_{1} = -\frac{1}{3} +\sqrt{2} ; x_{2} = -\frac{1}{3}-\sqrt{2}$

The graph below shows the roots at x₁ =1.081 and x₂ = -1.748.