Final answer:
The x-coordinate of the midpoint of line segment CD is found using the midpoint formula, resulting in an x-coordinate of 5, which is option c.
Step-by-step explanation:
To find the x-coordinate of the midpoint of line segment CD, with endpoints at (-4,-2) and (14,2), we use the midpoint formula which is defined as:
(x_{midpoint}, y_{midpoint}) = \left(\frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2}\right)
Substituting the given x-coordinates of the endpoints into this formula, we get:
x_{midpoint} = \frac{-4 + 14}{2} = \frac{10}{2} = 5
Therefore, the correct answer is option c. 5.