the point you are looking for belongs to the perpendicular bisector of the two given points and the straight line parallel to the x-axis with y = 3.
1. Calculate the midpoint between the given points: M(5, 1)
2. Calculate the slope of the line connecting the given points:
Therefore the perpendicular direction has the slope -2/3
3. Use point-slope-formula of a straight line:
4. Plug in this value for y and solve for x. You should get x = 2
So the point you are looking for is P(2, 3)
PS.: The 2nd problem is very similar to this one here. I leave for you.