The inequality is .

Apply addition property of inequality: Add 9 to each side.

             (Additive inverse property: )

                    (Additive identity property: )

                       (Add: )

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 or equal to 10 in .

                        (Substitute )

                                 (Substract: )

The inequality solution set is .