Select the correct answer.

Solve for [tex][tex]$x$[/tex][/tex].
[tex]x^2 - 2x - 24 = 0[/tex]

A. [tex]-4, -6[/tex]
B. [tex]-4, 6[/tex]
C. [tex]2, -6[/tex]
D. [tex]4, 6[/tex]



Answer :

To solve the equation [tex]\( x^2 - 2x - 24 = 0 \)[/tex], we can use the quadratic formula. The quadratic formula for solving equations of the form [tex]\( ax^2 + bx + c = 0 \)[/tex] is given by:

[tex]\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \][/tex]

Here, we identify the coefficients [tex]\( a \)[/tex], [tex]\( b \)[/tex], and [tex]\( c \)[/tex] from the given equation [tex]\( x^2 - 2x - 24 = 0 \)[/tex]. Specifically:
- [tex]\( a = 1 \)[/tex]
- [tex]\( b = -2 \)[/tex]
- [tex]\( c = -24 \)[/tex]

Now, substitute these values into the quadratic formula:

[tex]\[ x = \frac{-(-2) \pm \sqrt{(-2)^2 - 4 \cdot 1 \cdot (-24)}}{2 \cdot 1} \][/tex]

Simplify the expression step-by-step:

1. Compute the discriminant:
[tex]\[ (-2)^2 - 4 \cdot 1 \cdot (-24) = 4 + 96 = 100 \][/tex]

2. Take the square root of the discriminant:
[tex]\[ \sqrt{100} = 10 \][/tex]

3. Apply the quadratic formula:
[tex]\[ x = \frac{2 \pm 10}{2} \][/tex]

This gives us two potential solutions:
[tex]\[ x = \frac{2 + 10}{2} = \frac{12}{2} = 6 \][/tex]
[tex]\[ x = \frac{2 - 10}{2} = \frac{-8}{2} = -4 \][/tex]

Thus, the solutions to the equation [tex]\( x^2 - 2x - 24 = 0 \)[/tex] are:

[tex]\[ x = -4 \quad \text{and} \quad x = 6 \][/tex]

So, the correct answer is:
B. [tex]\( -4, 6 \)[/tex]