Solve Using the Quadratic Formula 4x^2-6x-6=0

$4 x^{2} - 6 x - 6 = 0$

Step 1

Use the quadratic formula to find the solutions.

$\frac{- b \pm \sqrt{b^{2} - 4 (a c)}}{2 a}$

Step 2

Substitute the values $a = 4$ , $b = - 6$ , and $c = - 6$ into the quadratic formula and solve for $x$ .

$\frac{6 \pm \sqrt{{(- 6)}^{2} - 4 \cdot (4 \cdot - 6)}}{2 \cdot 4}$

Step 3

Simplify.

Simplify the numerator.

Raise $- 6$ to the power of $2$ .

$x = \frac{6 \pm \sqrt{36 - 4 \cdot 4 \cdot - 6}}{2 \cdot 4}$

Multiply $- 4 \cdot 4 \cdot - 6$ .

Multiply $- 4$ by $4$ .

$x = \frac{6 \pm \sqrt{36 - 16 \cdot - 6}}{2 \cdot 4}$

Multiply $- 16$ by $- 6$ .

$x = \frac{6 \pm \sqrt{36 + 96}}{2 \cdot 4}$

Add $36$ and $96$ .

$x = \frac{6 \pm \sqrt{132}}{2 \cdot 4}$

Rewrite $132$ as $2^{2} \cdot 33$ .

Factor $4$ out of $132$ .

$x = \frac{6 \pm \sqrt{4 (33)}}{2 \cdot 4}$

Rewrite $4$ as $2^{2}$ .

$x = \frac{6 \pm \sqrt{2^{2} \cdot 33}}{2 \cdot 4}$

Pull terms out from under the radical.

$x = \frac{6 \pm 2 \sqrt{33}}{2 \cdot 4}$

Multiply $2$ by $4$ .

$x = \frac{6 \pm 2 \sqrt{33}}{8}$

Simplify $\frac{6 \pm 2 \sqrt{33}}{8}$ .

$x = \frac{3 \pm \sqrt{33}}{4}$

Step 4

The result can be shown in multiple forms.

Exact Form:

$x = \frac{3 \pm \sqrt{33}}{4}$

Decimal Form:

$x = 2.18614066 \dots, - 0.68614066 \dots$