Answer:
(-8, 7) reflected across the x-axis would be (-8, -7).
Explanation:
To reflect a point across the x-axis, all you have to do is invert the y-coordinate.
For the given point (-8, 7), the y-coordinate is 7. Just invert that number, meaning make a positive number into a negative, or a negative number into a positive.

(-8, 7) reflected across the x-axis would be (-8, -7).