The point-slope form:
[tex]y-y_1=m(x-x_1)[/tex]
We have the slope m = -2/3 and the point (-9, 3). Substitute:
[tex]y-3=-\dfrac{2}{3}(x-(-9))[/tex]
[tex]y-3=-\dfrac{2}{3}(x+9)[/tex] use distributive property
[tex]y-3=-\dfrac{2}{3}x-\dfrac{2}{3}\cdot9[/tex]
[tex]y-3=-\dfrac{2}{3}x-(2)(3)[/tex]
[tex]y-3=-\dfrac{2}{3}x-6[/tex] add 3 to both sides
[tex]\boxed{y=-\dfrac{2}{3}x-3}[/tex]