How do you solve x²+2x-24=0 using the quadratic formula?

1 Answer
Jul 10, 2015

x=9
or
x=-11

Explanation:

x^2+2x-24=0
is a quadratic equation of the generalized form:
color(white)("XXXX")ax^2+bx+c = 0
for which the roots are given by the quadratic formula:
color(white)("XXXX")x = (-b+-sqrt(b^2-4ac))/(2a)

Using the specific values of the given equation:
color(white)("XXXX")x = (-2+-sqrt(2^2-4(1)(-24)))/(2(1))

color(white)("XXXX")color(white)("XXXX")= (-2+-sqrt(4+96))/2

color(white)("XXXX")color(white)("XXXX")= (+9) or (-11)