Answer
$x = \frac{1}{2}, x = - \frac{9}{2}$
Work Step by Step
Given:
$4x^2+16x-9=0$
Use the Quadratic Equation Formula: $x = \frac{-b \pm \sqrt {b^2-4ac}}{2a}$
$4x^2+16x-9$
$a = 4, b = 16, c = -9$
$x = \frac{-(16) \pm \sqrt {(16)^2- 4(4 \times -9)}}{2(4)}$
$x = \frac{-16 \pm \sqrt {256+ 144}}{8}$
$x = \frac{-16 \pm \sqrt {400}}{8}$
$x = \frac{-16+20\ }{8}= \frac{1}{2}$
$x = \frac{-16-20\ }{8}= - \frac{9}{2}$