Respuesta :

line passing through (x1,y1) and (x2,y2) is (y2-y1)/(x2-x1)

slope is -1 and points are (2,3) and (5,y)

slope=(y-3)/(5-3)=-1
(y-3)/2=-1
times both sides by 2
y-3=-2
add 3 both sides
y=1


y=1