Y=mx+c where m is the gradient.
If the equation is perpendicular is -
Use y-y1=m(x-x1)
and you should get
y+1=- (x+4)
4y+4=-3x-12
y=-<span></span>x - 16
If the equation is perpendicular is -
Use y-y1=m(x-x1)
and you should get
y+1=-
4y+4=-3x-12
y=-<span>