Using the quadratic formula, find the solution to 3x2+18x+24=0 (1 point) Responses x=4 x is equal to 4 x=−2 x is equal to negative 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:

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

The quadratic formula is given by:

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

Now, we need to calculate the discriminant \(b^2 - 4ac\):

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

Now, we can plug the values into the quadratic formula:

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

Calculating the square root of the discriminant:

\[ \sqrt{36} = 6 \]

Now substituting this back into the formula:

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

This gives us two potential solutions:

  1. When we use the positive root:

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

  1. When we use the negative root:

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

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

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

Therefore, the correct answer from the choices given is:

x = −2, x = −4.