Find the coordinates of the mid-point AB where A (-3,-3) and B (1,3)

X coordinates = (-3+1)/2 = (-2)/2 = -1Y coordinates = (-3+3)/2 = (0) /2 = 0 Coordinates of the midpoint = (x,y) = (-1,0)
If they were struggling to visualise it/to avoid simple mistakes, I would suggest quickly sketching a graphI could then ask follow up questions such as what is the gradient, find the distance between the two points. etc etc OR ask them in a way they would see in their exam eg. find the equation of the line, giving your answer in the form ax + by + c = 0 where a, b and c are integers.