Instructions: Solve the quadratic equation.

[tex]\[ 4x^2 - 9x - 9 = 0 \][/tex]

[tex]\[ x = \square \text{ or } x = \square \][/tex]



Answer :

Certainly! Let's solve the quadratic equation step-by-step.

Given quadratic equation:
[tex]\[ 4x^2 - 9x - 9 = 0 \][/tex]

This is in the standard form [tex]\( ax^2 + bx + c = 0 \)[/tex] where [tex]\( a = 4 \)[/tex], [tex]\( b = -9 \)[/tex], and [tex]\( c = -9 \)[/tex].

To solve this equation, we will use the quadratic formula:
[tex]\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \][/tex]

First, let's identify the components that we need:

1. Calculate [tex]\( b^2 - 4ac \)[/tex]:

[tex]\[ b^2 - 4ac = (-9)^2 - 4(4)(-9) \][/tex]
[tex]\[ = 81 + 144 \][/tex]
[tex]\[ = 225 \][/tex]

2. Calculate the square root of [tex]\( b^2 - 4ac \)[/tex]:

[tex]\[ \sqrt{225} = 15 \][/tex]

3. Substitute [tex]\( a \)[/tex], [tex]\( b \)[/tex], and [tex]\(\sqrt{225}\)[/tex] back into the quadratic formula:

[tex]\[ x = \frac{-(-9) \pm 15}{2 \times 4} \][/tex]
[tex]\[ = \frac{9 \pm 15}{8} \][/tex]

Now, we have two possible solutions:
1. When [tex]\( + \)[/tex] is used:
[tex]\[ x = \frac{9 + 15}{8} = \frac{24}{8} = 3 \][/tex]

2. When [tex]\( - \)[/tex] is used:
[tex]\[ x = \frac{9 - 15}{8} = \frac{-6}{8} = -\frac{3}{4} \][/tex]

Hence, the solutions to the quadratic equation [tex]\( 4x^2 - 9x - 9 = 0 \)[/tex] are:
[tex]\[ x = -\frac{3}{4} \quad \text{or} \quad x = 3 \][/tex]