Question

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

Answer 1

`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)`