# How do you solve x^2 + 3 = –4x using the quadratic formula?

Apr 4, 2016

First you put everything to one side, by adding $4 x$

#### Explanation:

$\to {x}^{2} + 4 x + 3 = 0$

Quadratic formula: ${x}_{1 , 2} = \frac{- b \pm \sqrt{{b}^{2} - 4 a c}}{2 a}$

Or:
${x}_{1 , 2} = \frac{- 4 \pm \sqrt{{4}^{2} - 4 \cdot 1 \cdot 3}}{2 \cdot 1}$

${x}_{1 , 2} = \frac{- 4 \pm 2}{2} \to {x}_{1} = - 1 , {x}_{2} = - 3$

Extra:
Factoring would have been easier here:
$\left(x + 1\right) \left(x + 3\right) = 0$, with the same result.