It is also possible to determine an equation for a relation when you know information about the slope and/or points on the graph of the relation.

Example 2

The graph of a linear relation passes through the points (3,2) and (8,5). Determine the equation of the relation, in slope-intercept form.

To determine the m-value, the equation for slope can be used.

The equation of the relation will be of the form . Substituting the coordinates of any point on the graph of the relation into the equation must make it true, so substitute one of the known points into and solve for b. Here, (3,2) is used.

Now use the known m and b-values to write the equation of the relation.