The drama club is selling tickets to their play to raise money for the show's expenses. Each student ticket sells for $5 and each adult ticket sells for $10. The auditorium can hold at most 120 people. The drama club must make no less than $810 from ticket sales to cover the show's costs. Also, they can sell a maximum of 30 student tickets and at most 90 adult tickets. If xx represents the number of student tickets sold and yy represents the number of adult tickets sold, write and solve a system of inequalities graphically and determine one possible solution.