# How do you solve 8x(2x-1)=-1 using the quadratic formula?

Mar 14, 2018

The answer is $x = \frac{1}{4}$.

#### Explanation:

Expand the multiplication using the distributive property:

$8 x \left(2 x - 1\right) = - 1$

$16 {x}^{2} - 8 x = - 1$

$16 {x}^{2} - 8 x + 1 = 0$

$x = \frac{- \left(- 8\right) \pm \sqrt{{\left(- 8\right)}^{2} - 4 \left(16\right) \left(1\right)}}{2 \left(16\right)}$

$\textcolor{w h i t e}{x} = \frac{8 \pm \sqrt{64 - 64}}{32}$

$\textcolor{w h i t e}{x} = \frac{8 \pm \sqrt{0}}{32}$

$\textcolor{w h i t e}{x} = \frac{8 \pm 0}{32}$

$\textcolor{w h i t e}{x} = \frac{8}{32}$

$\textcolor{w h i t e}{x} = \frac{1}{4}$

That is the solution, hope this helped!