# How do you solve x^2 + 5x + 4 = 0 ?

Jul 25, 2017

You would factorise the equation first into this form
$\left(x + k\right) \left(x + r\right) = 0$

To do this you ask yourself this

What times what equals to 4
$k \cdot r = 4$

And what adds together to get 5
$k + r = 5$

$k = 1$
$r = 4$

$\left(x + 1\right) \left(x + 4\right) = 0$

$x = - 1$
$x = - 4$