The line equation in slope-intercept form is ,

where m is the slope and b is the y-intercept.

Write the two functions as co-ordinates

as

as

First find the slope

m =

    =          (Substitute and )

   =                 (Product of two same signs is positive)­­

    =                       (Add: )­­

The line crosses the y-axis at . So the y-intercept is .

Substitute and in slope-intercept form line equation.

              (Simplify)

The function is .