Respuesta :

for
(x1,y1) and (x2,y2)
slope=(y2-y1)/(x2-x1)

(1,-4)
(4,2)
x1=1
y1=-4
x2=4
y2=2

slope=(2-(-4))/(4-1)=(2+4)/3=6/3=2

slope=2