Solve Using the Quadratic Formula 2x^2-6x+7=0

$2 x^{2} - 6 x + 7 = 0$

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 $a = 2$ , $b = - 6$ , and $c = 7$ into the quadratic formula and solve for $x$ .

$\frac{6 \pm \sqrt{{(- 6)}^{2} - 4 \cdot (2 \cdot 7)}}{2 \cdot 2}$

Step 3

Simplify.

Simplify the numerator.

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

$x = \frac{6 \pm \sqrt{36 - 4 \cdot 2 \cdot 7}}{2 \cdot 2}$

Multiply $- 4 \cdot 2 \cdot 7$ .

Multiply $- 4$ by $2$ .

$x = \frac{6 \pm \sqrt{36 - 8 \cdot 7}}{2 \cdot 2}$

Multiply $- 8$ by $7$ .

$x = \frac{6 \pm \sqrt{36 - 56}}{2 \cdot 2}$

Subtract $56$ from $36$ .

$x = \frac{6 \pm \sqrt{- 20}}{2 \cdot 2}$

Rewrite $- 20$ as $- 1 (20)$ .

$x = \frac{6 \pm \sqrt{- 1 \cdot 20}}{2 \cdot 2}$

Rewrite $\sqrt{- 1 (20)}$ as $\sqrt{- 1} \cdot \sqrt{20}$ .

$x = \frac{6 \pm \sqrt{- 1} \cdot \sqrt{20}}{2 \cdot 2}$

Rewrite $\sqrt{- 1}$ as $i$ .

$x = \frac{6 \pm i \cdot \sqrt{20}}{2 \cdot 2}$

Rewrite $20$ as $2^{2} \cdot 5$ .

Factor $4$ out of $20$ .

$x = \frac{6 \pm i \cdot \sqrt{4 (5)}}{2 \cdot 2}$

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

$x = \frac{6 \pm i \cdot \sqrt{2^{2} \cdot 5}}{2 \cdot 2}$

Pull terms out from under the radical.

$x = \frac{6 \pm i \cdot (2 \sqrt{5})}{2 \cdot 2}$

Move $2$ to the left of $i$ .

$x = \frac{6 \pm 2 i \sqrt{5}}{2 \cdot 2}$

Multiply $2$ by $2$ .

$x = \frac{6 \pm 2 i \sqrt{5}}{4}$

Simplify $\frac{6 \pm 2 i \sqrt{5}}{4}$ .

$x = \frac{3 \pm i \sqrt{5}}{2}$