Explanation:
When reflecting a point across an axis, that means the opposite coordinate will switch signs.
Reflecting a point across the YAXIS means that the X coordinate will switch signs
Reflecting a point across the XAXIS means that the Y coordinate will switch signs
Taking (-3, -8)....
Reflecting it across the y-axis, we will flip the sign of the X coordinate. It's -3, so we make that +3, giving us
(3, -8)
Reflecting across the x-axis, we will flip the sign of the Y coordinate. it's -8, so we make that +8, giving us
(-3, 8)