The inequality is .

Subtract 12 from each side.

Divide each side by and flip the symbol.

The solution set is .

Check:

To check, substitute three different values for k into the original inequality: negative 9, a number less than negative 9, and greater than negative 9.

Let three values are substitute in the original inequality, .

If then      (This is false)

If then      (This is false)

If then     (This is true)

The solution set is .