# How do you solve using the completing the square method x^2 - 2x -3 = 0 ?

Mar 5, 2018

$x = 3 \text{ }$ or $\text{ } x = - 1$

#### Explanation:

$0 = {x}^{2} - 2 x - 3$

$\textcolor{w h i t e}{0} = {x}^{2} - 2 x + 1 - 4$

$\textcolor{w h i t e}{0} = {\left(x - 1\right)}^{2} - {2}^{2}$

$\textcolor{w h i t e}{0} = \left(\left(x - 1\right) - 2\right) \left(\left(x - 1\right) + 2\right)$

$\textcolor{w h i t e}{0} = \left(x - 3\right) \left(x + 1\right)$

Hence:

$x = 3 \text{ }$ or $\text{ } x = - 1$