So base on your question that ask to provide and end point of the four statement you give:
1.Endpoint(-1,9), midpoint:(-9,-10) - (-17, -29)
2.Endpoint(2,5), midpoint(5,1) - (4,5)
3.Endpoint(9,-10), midpoint(4,8) - i cant determine sorry
4.Find the point that is one-fourth of the way from (2,4) to (10,8) - also i cant.