Given points are

Next, find the slope.

Substitute 9 for y₂,  3 for y₁, 2 for x₂, and 1 for x₁  in slope formula.

                  (Product of two same signs is positive)

                  (Add: )

                        (Subtract: )

                           (Divide: )

You know the slope and a point on the line, so use point - slope form

with either given point to write an equation of line.

Choose

            (Substitute 9 for y₁, 2 for x₁ and )   

         (Apply distributive property: )

                (Multiply: )

   (Add 9 to each side)

         (Apply additive inverse property: )

                (Apply additive identity property: )

                      (Add: )

The equation of line is .