Answer:
1. (b,c)
2. (a+b,c)
3. 0
4. 0
5. midsegment
Explanation:
1. If X is a midpointt of the segment PQ, then its coordinates are

2. If X is a midpointt of the segment RQ, then its coordinates are

3. The slope of the line passing through the points X and Y is

4. Since lines XY and PR are parallel, then they have the same slopes. Thus, the slope of the line PR is 0.
Question 2. You are right, XY is a midsegment (by definition).