In physical education class, Ariel shoots free throws and lay-ups. She earns 1 point for each free throw she makes and 2 points for each lay-up she makes. The greatest number of points that she can earn is 30. She has to make at least 15 free throws and lay-ups altogether. One of the inequalities would be 1x + 2y < 30 where x represents the number of free throws made and y represents the number of lay-ups made. Write the other inequality for the system of inequalities that describes the constraints.