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
<em>*To solve for a variable, you have to isolate the desired variable onto 1 side</em>
So firstly, subtract 2p on both sides of the equation: 
Next, subtract b on both sides of the equation, and <u>your answer will be
</u>