Using the quadratic formula, find the solution to 3x^2+18x+24=0

.(1 point)
Responses

x=−2
x equals negative 2

x=−2
, x=−4
x equals negative 2 , x equals negative 4

x=4
, x=2
x equals 4 , x equals 2

x=−4

1 answer

To solve the quadratic equation \(3x^2 + 18x + 24 = 0\) using the quadratic formula, we will first identify the coefficients:

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

The quadratic formula is given by:

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

Now, let's calculate the discriminant:

\[ b^2 - 4ac = 18^2 - 4 \cdot 3 \cdot 24 = 324 - 288 = 36 \]

Now that we have the discriminant, we can plug it into the formula:

\[ x = \frac{-18 \pm \sqrt{36}}{2 \cdot 3} \]

Calculating the square root of 36:

\[ \sqrt{36} = 6 \]

Now substituting that back into the equation:

\[ x = \frac{-18 \pm 6}{6} \]

Now, we will calculate the two possible values for \(x\):

  1. Using the plus sign:

\[ x = \frac{-18 + 6}{6} = \frac{-12}{6} = -2 \]

  1. Using the minus sign:

\[ x = \frac{-18 - 6}{6} = \frac{-24}{6} = -4 \]

Thus, the solutions to the equation \(3x^2 + 18x + 24 = 0\) are:

\[ x = -2 \quad \text{and} \quad x = -4 \]

So the correct response is:

x=−2, x=−4
(x equals negative 2 , x equals negative 4)