Answer with explanation:
It is given that coordinate of A is 0 , AR=5 and AT=7.
This is one dimensional plane.
Suppose a line segment has length , a , then mid point of line segment is given by
Mid Point of Segment AR will be
Mid Point of Segment AT will be
Now, you have used the term coordinates , it means you are talking about two dimensional plane.
So, Coordinates of Mid point of AR can be =(2.5,0) and (-2.5,0).
And, Coordinates of Mid point of AT can be =(3.5,0) and (-3.5,0).