The inequality is .

Apply subtration  property of inequality: Subtract 18 from each side.

            (Commutative property:  a + b = b + a)

                      (Additive inverse property:  )

                             (Additive identity property:  )

                                    (Subtract: )

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 greater than 3 in .

                                (Substitute  )

                                         (Add: )

The inequality is true.

The inequality solution set is .