Solve the quadratic equation: [tex]\(x^2 - 8x + 24 = 4\)[/tex].

A. [tex]\((8 + 4i, 8 - 4i)\)[/tex]
B. [tex]\((-4 + 2i, -4 - 2i)\)[/tex]
C. [tex]\((4 + 2i, 4 - 2i)\)[/tex]
D. [tex]\((-8 + 4i, -8 - 4i)\)[/tex]



Answer :

To solve the quadratic equation [tex]\(x^2 - 8x + 24 = 4\)[/tex], let's follow these steps:

1. Subtract 4 from both sides of the equation:

[tex]\[ x^2 - 8x + 24 - 4 = 0 \][/tex]

Simplifying this, we get:

[tex]\[ x^2 - 8x + 20 = 0 \][/tex]

2. Identify the coefficients for the quadratic formula:

The quadratic formula is given by:

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

For our equation [tex]\(x^2 - 8x + 20 = 0\)[/tex], the coefficients are:
- [tex]\(a = 1\)[/tex]
- [tex]\(b = -8\)[/tex]
- [tex]\(c = 20\)[/tex]

3. Calculate the discriminant:

The discriminant [tex]\(\Delta\)[/tex] is:

[tex]\[ \Delta = b^2 - 4ac \][/tex]

Substituting the coefficients, we get:

[tex]\[ \Delta = (-8)^2 - 4 \cdot 1 \cdot 20 = 64 - 80 = -16 \][/tex]

The discriminant is [tex]\(-16\)[/tex], which is negative. This indicates that the solutions will be complex numbers.

4. Calculate the solutions using the quadratic formula:

[tex]\[ x = \frac{-(-8) \pm \sqrt{-16}}{2 \cdot 1} = \frac{8 \pm \sqrt{-16}}{2} \][/tex]

Recall that [tex]\(\sqrt{-16} = 4i\)[/tex], where [tex]\(i\)[/tex] is the imaginary unit. Therefore:

[tex]\[ x = \frac{8 \pm 4i}{2} \][/tex]

5. Simplify the solutions:

[tex]\[ x = \frac{8}{2} \pm \frac{4i}{2} = 4 \pm 2i \][/tex]

Therefore, the solutions to the quadratic equation [tex]\(x^2 - 8x + 24 = 4\)[/tex] are [tex]\(x = 4 + 2i\)[/tex] and [tex]\(x = 4 - 2i\)[/tex].

Hence, the correct answer is:

C. [tex]\( (4 + 2i, 4 - 2i) \)[/tex]