Respuesta :

(y-y1)/(x-x1)=(y-y2)(x-x2)
(y-7)/(x+3)=(y-5)/(x+1)
(y-7)(x+1)=(y-5)(x+3)
yx-7x+y-7=yx-5x+3y-15
4y=-2x+8
y=-x+4