First off, we need the slope
[tex]\frac{y2-y1}{x2-x1}[/tex]
[tex]\frac{8-(-4)}{1-(-2)}[/tex]
That leaves you with
12/3 = 4
point-slope form: y-y1 = m ( x - x1)
So...
y - (-4) = 4 ( x - (-2))
y + 4 = 4 (x + 2)
y + 4 = 4x + 8
Now subtract 4 from both sides of the equation
y = 4x +4