The first step is to find the slope of the line between the two points using the slope formula:
[tex]m= \dfrac{y_2-y_1}{x_2-x_1}[/tex]
Using that formula for your points, you'd have:
[tex]m= \dfrac{4-6}{3-1} = \dfrac{-2}{2} = -1[/tex]
The second step is to remember the point-slope form, [tex]y-y_1 = m(x-x_1)[/tex] and then plug in the slope we just found and one of the points, say (1,6).
[tex]y-6 = -1(x-1)[/tex] or [tex]y-6 = -(x-1)[/tex]
An equally correct answer, using the other point of (3,4) would be:
[tex]y-4 = -(x-3)[/tex]
