Connect with a knowledgeable community and get your questions answered on IDNLearn.com. Find reliable solutions to your questions quickly and accurately with help from our dedicated community of experts.

Select the correct answer.

Solve the equation.
[tex]\[ 3x^2 + 24x - 24 = 0 \][/tex]

A. [tex]\(x = 4 \pm 2\sqrt{6}\)[/tex]

B. [tex]\(x = -2 \pm 4\sqrt{6}\)[/tex]

C. [tex]\(x = -4 \pm 2\sqrt{6}\)[/tex]

D. [tex]\(x = 2 \pm 4\sqrt{6}\)[/tex]


Sagot :

To solve the quadratic equation [tex]\( 3x^2 + 24x - 24 = 0 \)[/tex], let's follow a detailed, step-by-step solution.

### Step 1: Identify the coefficients
The given quadratic equation is of the form:

[tex]\[ a x^2 + b x + c = 0 \][/tex]

where [tex]\( a = 3 \)[/tex], [tex]\( b = 24 \)[/tex], and [tex]\( c = -24 \)[/tex].

### Step 2: Use the quadratic formula
The quadratic formula for solving [tex]\( ax^2 + bx + c = 0 \)[/tex] is:

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

### Step 3: Calculate the discriminant
The discriminant ([tex]\( \Delta \)[/tex]) is given by:

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

Substitute [tex]\( a = 3 \)[/tex], [tex]\( b = 24 \)[/tex], and [tex]\( c = -24 \)[/tex]:

[tex]\[ \Delta = 24^2 - 4 \cdot 3 \cdot (-24) \][/tex]
[tex]\[ \Delta = 576 + 288 \][/tex]
[tex]\[ \Delta = 864 \][/tex]

### Step 4: Calculate the square root of the discriminant
[tex]\[ \sqrt{\Delta} = \sqrt{864} \][/tex]
[tex]\[ \sqrt{864} = \sqrt{144 \cdot 6} = 12 \sqrt{6} \][/tex]

### Step 5: Apply the quadratic formula
Substitute [tex]\( b = 24 \)[/tex], [tex]\( \sqrt{\Delta} = 12 \sqrt{6} \)[/tex], and [tex]\( a = 3 \)[/tex] into the quadratic formula:

[tex]\[ x = \frac{-24 \pm 12 \sqrt{6}}{6} \][/tex]

### Step 6: Simplify the expression
Separate the fraction:

[tex]\[ x = \frac{-24}{6} \pm \frac{12 \sqrt{6}}{6} \][/tex]
[tex]\[ x = -4 \pm 2 \sqrt{6} \][/tex]

### Step 7: Write the final solutions
The solutions to the quadratic equation [tex]\( 3x^2 + 24x - 24 = 0 \)[/tex] are:

[tex]\[ x = -4 + 2 \sqrt{6} \quad \text{and} \quad x = -4 - 2 \sqrt{6} \][/tex]

Checking the given options:

A. [tex]\( x = 4 \pm 2 \sqrt{6} \)[/tex]
B. [tex]\( x = -2 \pm 4 \sqrt{6} \)[/tex]
C. [tex]\( x = -4 \pm 2 \sqrt{6} \)[/tex]
D. [tex]\( x = 2 \pm 4 \sqrt{6} \)[/tex]

### Step 8: Select the correct answer
Thus, the correct answer is:

C. [tex]\( x = -4 \pm 2 \sqrt{6} \)[/tex]