Solve [tex]$9(2x-3)^2 + 7 = 448$[/tex]

A) [tex]$x = \pm 5$[/tex]
B) [tex][tex]$x = 5, -2$[/tex][/tex]
C) [tex]$x = -5, 2$[/tex]
D) [tex]$x = 5, 0$[/tex]



Answer :

Let's solve the equation [tex]\(9(2x - 3)^2 + 7 = 448\)[/tex] step-by-step:

1. Isolate the quadratic term:

We start by subtracting 7 from both sides of the equation:
[tex]\[ 9(2x - 3)^2 + 7 - 7 = 448 - 7 \][/tex]
This simplifies to:
[tex]\[ 9(2x - 3)^2 = 441 \][/tex]

2. Divide by 9:

Next, we divide both sides of the equation by 9 to further isolate the squared term:
[tex]\[ \frac{9(2x - 3)^2}{9} = \frac{441}{9} \][/tex]
Simplifying this, we get:
[tex]\[ (2x - 3)^2 = 49 \][/tex]

3. Take the square root of both sides:

To solve for the expression inside the square, we take the square root of both sides. Remember to consider both the positive and negative roots:
[tex]\[ 2x - 3 = \pm \sqrt{49} \][/tex]
Since [tex]\(\sqrt{49} = 7\)[/tex], we have:
[tex]\[ 2x - 3 = 7 \quad \text{or} \quad 2x - 3 = -7 \][/tex]

4. Solve for [tex]\(x\)[/tex]:

Now we solve each of these equations separately:

For [tex]\(2x - 3 = 7\)[/tex]:
[tex]\[ 2x - 3 = 7 \][/tex]
Add 3 to both sides:
[tex]\[ 2x = 10 \][/tex]
Divide by 2:
[tex]\[ x = 5 \][/tex]

For [tex]\(2x - 3 = -7\)[/tex]:
[tex]\[ 2x - 3 = -7 \][/tex]
Add 3 to both sides:
[tex]\[ 2x = -4 \][/tex]
Divide by 2:
[tex]\[ x = -2 \][/tex]

Thus, the solutions to the equation [tex]\(9(2x - 3)^2 + 7 = 448\)[/tex] are [tex]\(x = 5\)[/tex] and [tex]\(x = -2\)[/tex].

So the correct answer is:

B) [tex]\(x = 5, -2\)[/tex]