How do you solve $x^2 +2x -4=0$ ?

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Answer 1 · 2015-09-12T07:14:38

The solutions are
$color(blue)(x=-1+sqrt(5)$
$color(blue)(x=-1-sqrt(5)$

$x^2 +2x -4=0$

The equation is of the form $color(blue)(ax^2+bx+c=0$ where:
$a=1, b=2, c=-4$

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

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

$= 4 +16 = 20$

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

$x = ((-2)+-sqrt(20))/(2*1) = (-2+-2sqrt(5))/2$

$=(cancel2(-1+-sqrt(5)))/cancel2$

The solutions are
$color(blue)(x=-1+sqrt(5)$
$color(blue)(x=-1-sqrt(5)$

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