There are four points that are 5 units from the line y=13 and 18 units from the point (7,15). What is the sum of the x and y and coordinates of all four of these points?
Point:=$(a,b)$. Then $b=13\pm 5$.
If $b=18$: $(a,18)\to (7,15)=18$. So $(a-7)^2=18^2-9$. Finish from here
If $b=8$: Same thing