Use point -slope form of equation of line:
[tex]y - y_0 = m(x-x_0) \\ \\ (x_0,y_0) = (-15,0) \\ \\ y = m(x+15)[/tex]
Next determine perpendicular slope.
Slope of given line is 5.
Perpendicular slopes must multiply to -1.
---> 5m = -1
---> m = -1/5
Sub into line equation for 'm'.
[tex]y = -\frac{1}{5} (x+15) \\ \\ y = -\frac{1}{5} x - 3[/tex]
