Using the quadratic formula, find the solution to 3x2+18x+24=0

3
𝑥
2
+
18
𝑥
+
24
=
0
(1 point)
Responses

x=4
𝑥
=
4
x is equal to 4

x=−2
𝑥
=

2
x is equal to negative 2

x=4, x=2
𝑥
=
4
,

𝑥
=
2
x=4, x=2
𝑥
=
4
,

𝑥
=
2

x=−2, x=−4

1 answer

To solve the quadratic equation \( 3x^2 + 18x + 24 = 0 \) using the quadratic formula, we start by identifying the coefficients in the standard form of a quadratic equation \( ax^2 + bx + c = 0 \).

Here, we have:

  • \( a = 3 \)
  • \( b = 18 \)
  • \( c = 24 \)

The quadratic formula is given by: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \]

Now we can substitute the values of \( a \), \( b \), and \( c \):

  1. Calculate the discriminant \( b^2 - 4ac \): \[ b^2 = 18^2 = 324 \] \[ 4ac = 4 \times 3 \times 24 = 288 \] \[ b^2 - 4ac = 324 - 288 = 36 \]

  2. Now substitute into the quadratic formula: \[ x = \frac{-18 \pm \sqrt{36}}{2 \times 3} \] \[ \sqrt{36} = 6 \] \[ x = \frac{-18 \pm 6}{6} \]

  3. This gives us two solutions:

    • First solution: \[ x = \frac{-18 + 6}{6} = \frac{-12}{6} = -2 \]
    • Second solution: \[ x = \frac{-18 - 6}{6} = \frac{-24}{6} = -4 \]

Thus, the solutions to the equation \( 3x^2 + 18x + 24 = 0 \) are: \[ x = -2 \quad \text{and} \quad x = -4 \]

Therefore, the correct response is: x = -2, x = -4.