We have a figure that is reflected across the x-axis.
If we have a point P = (x,y) that is reflected across the x-axis, the coordinates of the image will be (x,-y) as the x-coordinate stays the same and the y-coordinate has the same absolute value but opposite sign.
We identify the dot at coordinates P = (3,7).
Then, its image will be P' = (3,-7).
Answer:
Point in the original figure = (3, 7)
Point in the final figure = (3, -7)