Anna is selling tickets to her tennis tournament. An adult ticket costs $20 and a student ticket costs $16. Anna collects $1020 for a total of 55 tickets. How many adult and how many student tickets has Anna sold?

For this problem you need to create a system of equations. So say the variable for adult tickets is x and the variable for student tickets is y. The first equation would be for the number of tickets and that equation would look like x+y=55. The second equation would be for money and would look like 20x+16y=1020. So put 20x+16y=1020 on top of x+y=55 and subtract x+y=55.