Using the quadratic formula, find the solution to 3x2+18x+24=0.(1 point)

Responses

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

x=−4
x equals negative 4

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

x=−2

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:

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

First, calculate the discriminant:

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

Next, since the discriminant is positive, we will have two real solutions. Now plug the values into the quadratic formula:

\[ x = \frac{{-18 \pm \sqrt{36}}}{{2 \cdot 3}} \] \[ = \frac{{-18 \pm 6}}{{6}} \]

Calculate the two solutions:

  1. \( x = \frac{{-18 + 6}}{6} = \frac{{-12}}{6} = -2 \)

  2. \( x = \frac{{-18 - 6}}{6} = \frac{{-24}}{6} = -4 \)

So the solutions are:

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

Thus, the response is:

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