Using the quadratic formula, find the solution to x2−6x−16=0

.(1 point)
Responses

x=8
, x=−2
x equals 8 , x equals negative 2

x=8
, x=−8
x equals 8 , x equals negative 8

x=−2
x equals negative 2

x=8

1 answer

To solve the quadratic equation \( x^2 - 6x - 16 = 0 \) using the quadratic formula, we start with the standard form of a quadratic equation:

\[ ax^2 + bx + c = 0 \]

In this case, \( a = 1 \), \( b = -6 \), and \( c = -16 \).

The quadratic formula is given by:

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

Let's compute the values step-by-step:

  1. Calculate \( b^2 - 4ac \):

\[ b^2 = (-6)^2 = 36 \] \[ 4ac = 4 \cdot 1 \cdot (-16) = -64 \] \[ b^2 - 4ac = 36 - (-64) = 36 + 64 = 100 \]

  1. Now substituting back into the quadratic formula:

\[ x = \frac{{-(-6) \pm \sqrt{100}}}{2 \cdot 1} \] \[ x = \frac{{6 \pm 10}}{2} \]

  1. This gives us two potential solutions:

\[ x_1 = \frac{{6 + 10}}{2} = \frac{16}{2} = 8 \]

\[ x_2 = \frac{{6 - 10}}{2} = \frac{-4}{2} = -2 \]

Thus, the solutions to the equation \( x^2 - 6x - 16 = 0 \) are:

\[ x = 8, \quad x = -2 \]

So, the correct response is:

x equals 8, x equals negative 2.