Solve the equation:

[tex]\[ 6(2x + 4)^2 = (2x + 4) + 2 \][/tex]

Choose the correct solution:

A. [tex]\( x = -\frac{5}{3} \)[/tex] or [tex]\( -\frac{9}{4} \)[/tex]

B. [tex]\( x = -\frac{5}{3} \)[/tex] or [tex]\( \frac{9}{4} \)[/tex]

C. [tex]\( x = \frac{5}{3} \)[/tex] or [tex]\( -\frac{9}{4} \)[/tex]

D. [tex]\( x = \frac{5}{3} \)[/tex] or [tex]\( \frac{9}{4} \)[/tex]



Answer :

Let's solve the equation [tex]\( 6(2x + 4)^2 = (2x + 4) + 2 \)[/tex] step by step.

1. Expand and simplify the equation:

Rewrite the given equation:
[tex]\[ 6(2x + 4)^2 = (2x + 4) + 2 \][/tex]

2. Multiply out the left-hand side:

[tex]\( 6(2x + 4)^2 \)[/tex] involves squaring [tex]\( 2x+4 \)[/tex] first:
[tex]\[ (2x + 4)^2 = (2x + 4)(2x + 4) = 4x^2 + 16x + 16 \][/tex]

Now, multiply by 6:
[tex]\[ 6(4x^2 + 16x + 16) = 24x^2 + 96x + 96 \][/tex]

3. Combine terms on both sides:

Substitute this back into the equation:
[tex]\[ 24x^2 + 96x + 96 = (2x + 4) + 2 \][/tex]
Simplify the right-hand side:
[tex]\[ 2x + 4 + 2 = 2x + 6 \][/tex]

Hence, the equation is:
[tex]\[ 24x^2 + 96x + 96 = 2x + 6 \][/tex]

4. Move all terms to one side to set the equation to 0:

[tex]\[ 24x^2 + 96x + 96 - 2x - 6 = 0 \][/tex]

Combine like terms:
[tex]\[ 24x^2 + 94x + 90 = 0 \][/tex]

5. Solve the quadratic equation:

To solve [tex]\( 24x^2 + 94x + 90 = 0 \)[/tex], we use the quadratic formula:
[tex]\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \][/tex]
where [tex]\( a = 24 \)[/tex], [tex]\( b = 94 \)[/tex], and [tex]\( c = 90 \)[/tex].

First, compute the discriminant:
[tex]\[ b^2 - 4ac = 94^2 - 4 \times 24 \times 90 \][/tex]

Calculating each term:
[tex]\[ 94^2 = 8836 \][/tex]

[tex]\[ 4 \times 24 \times 90 = 8640 \][/tex]

Therefore:
[tex]\[ 8836 - 8640 = 196 \][/tex]

6. Find the square root of the discriminant:

[tex]\[ \sqrt{196} = 14 \][/tex]

7. Substitute into the quadratic formula:

[tex]\[ x = \frac{-94 \pm 14}{48} \][/tex]

Calculate the two possible solutions:

For [tex]\( x = \frac{-94 + 14}{48} = \frac{-80}{48} = -\frac{5}{3} \)[/tex]

For [tex]\( x = \frac{-94 - 14}{48} = \frac{-108}{48} = -\frac{9}{4} \)[/tex]

Therefore, the solutions to the equation [tex]\( 6(2 x+4)^2 = (2 x+4) + 2 \)[/tex] are:
[tex]\[ x = -\frac{5}{3} \quad \text{and} \quad x = -\frac{9}{4} \][/tex]