Write an equation of a line containing (2, 1) and (3, 4) in point-slope form.

Note that points are: (x₁,y₁), (x₂,y₂)

Your equation is:

(y₂ - y₁)/(x₂ - x₁) = Slope

Let:
(2,1) = (x₁,y₁)
(3,4) = (x₂,y₂)

Plug into corresponding numbers

(4 - 1)/(3 - 2) = 3/1

3/1 is your slope

hope this helps