Find the slope, which is the change in y over the change in x:
Slope = (-2 -6) / ( 3 - -6) = -8/9
Now write the equation in point slope form y - y1=m(x-x1) :
Y- 6 = -8/9(x - -6)
Simplify:
Y -6 = -8/9(x+6)
Now write in standard for Ax + Bx = C
8x +9y = 6