Hello from MrBillDoesMath!
Answer: The point (5, -1)
Discussion :
Per the author, the point wanted it at the intersection of the horizontal line passing through (2,-1) and the vertical line passing through (5,7).
The horizontal line passing through (2, -1) has y = -1 and the vertical line passing through (5,7) has x = 5. So their intersection is the point (5.,-1)
Regards, MrB