# How do you solve using the completing the square method x^2-4x+2=0?

Apr 11, 2017

$y = {\left(x - 2\right)}^{2} - 2$

#### Explanation:

The completing the square form is:
$y = {\left(x + a\right)}^{2} + b$

The "a" term will be equal to the middle term divided by two. I.e. $- \frac{4}{2} = - 2$.

This means that you now have the following:

$y = {\left(x - 2\right)}^{2} + b$

Because the completing the square form is equivalent to your original equation you have:

x^2−4x+2=(x-2)^2+b
x^2−4x+2=x^2-4x+4+b <-- I expanded the right-hand side
$b = - 2$ <--After simplifying you can find the "b"-term