Answer:
Therefore, the coordinates of the midpoint M are (1, 8).
Explanation:
The midpoint formula is:
M = ((x1 + x2)/2, (y1 + y2)/2)
where (x1, y1) and (x2, y2) are the coordinates of the endpoints.
Using this formula, we have:
M = ((1 + 1)/2, (7 + 9)/2) = (1, 8)
Therefore, the coordinates of the midpoint M are (1, 8).