The inequality is .

Apply multiplication property of inequality: Multiply each side by 3.

                   (Cancel common terms)

                     (Multiply: )

      (Multiply each side by negative one and flip the symbol)

                            (Product of two same signs is positive sign)

Graph the solution set on a number line.

Note: A dot means that this point is included in the solution set.

Check:

To check, substitute a number less than 15 in inequality .

                     (Substitute   )

                        (Divide:  )

The inequality is true.

The inequality solution set is .