How do you solve $x^2=-5x-5$ ?

Question

1481 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-08-01T18:16:38

$color(red)(x=(sqrt5-5)/2)$ and $color(red)(x = -(sqrt5+5)/2)$

$x^2 = -5x-5$

Convert the equation to standard form,

$ax^2 + bx +c =0$

$x^2 + 5x+5 = 0$

$a=1$ , $b=5$ , and $c=5$

$x = (-b±sqrt(b^2 -4ac))/(2a) = (-5±sqrt(5^2-4×1×5))/(2×1) = (-5±sqrt(25-20))/2 = (-5±sqrt5)/2$

$x=(-5+sqrt5)/2$ and $x=(-5-sqrt5)/2$

or

$x=(sqrt5-5)/2$ and $x = -(sqrt5+5)/2$

How do you solve x^2=-5x-5 x^2=-5x-5?