The original function is

Write as or

First solve the case .

Apply Addition property of equality: if a = b, then a + c = b + c.

               (Add 3 to each side)

                     (Additive inerse property: )

                           (Additive identity property: )

                                 (Add: ) .

Apply Addition property of equality: if a = b, then .

                             (Divide each side by 3)

                                 (Cancel commen terms)

                                      (Divide: )

Next solve the case .

Apply Addition property of equality: if a = b, then a + c = b + c..

        (Add 3 to each side)

              (Additive inerse property: )

                    (Additive identity property: )

                             (Add: ) .

Apply Addition property of equality: if a = b, then .

                         (Divide each side by 3)

                              (Cancel commen terms)

                                 (Divide: )

First, draw a number line.

To graph the solutions set, mark the numbers -3 and  1 on number line.

The solution set is .