How do you solve $x^2 - 2x - 5 = 0$ ?

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Answer 1 · 2015-09-12T07:09:54

The solutions are:
$color(blue)(=1+sqrt(6)$

$color(blue)(=1-sqrt(6)$

$x^2−2x−5=0$

The equation is of the form $color(blue)(ax^2+bx+c=0$ where:
$a=1, b=-2, c= -5$

The Discriminant is given by:
$Delta=b^2-4*a*c$

$= (-2)^2-(4*1* (-5))$

$= 4 +20 = 24$

The solutions are found using the formula
$x=(-b+-sqrtDelta)/(2*a)$

$x = (-(-2)+-sqrt(24))/(2*1) = (2+-2sqrt(6))/2$

$=(cancel2(1+-sqrt(6)))/cancel2$

The solutions are:
$color(blue)(=1+sqrt(6)$

$color(blue)(=1-sqrt(6)$

How do you solve x^2 - 2x - 5 = 0x^2 - 2x - 5 = 0?