The midpoint of a line segment is . If one endpoint of the line segment is , what is the other endpoint?

Suppose the midpoint of a line segment is What are the endpoints of the segment?

If is the midpoint of and another point, what is that other point?

What is the midpoint of the segment of

between and ?

If is the midpoint of and another point, what is that other point?

In the standard (x,y) coordinate plane, the midpoint of line XY is (12, **–**3) and point X is located at (3, 4). What are the coordinates of point Y?