What is the point-slope of a line with slope -3 that contains the point (1,2)

The point slope form of a line is:

(y-y1)=m(x-x1)  (1)
where 
m=slope = -3 for this problem.
(x1,y1) is a point contained in the line, which equals (1,2) for this problem.
Substitute m, x1, y1 into equation (1) to get the equation of the line in point slope form.

Its d so thats how it would would back from 1.0 form three four two