Write a Linear Function

Directions: Using the digits 1 through 8 [You will use each number only once, except for one number that will be used twice in the same coordinate point. i.e.(1,1), (2,2), (3,3), (4,4), (5,5), (6,6), (7,7) or (8,8)], find three coordinate points that lie on the same line. Write the equation of the line represented by the three points and have the following requirements:
a.) It has a positive slope
b.) The slope is less than one.

Source: Jeanmarie Mullen