Answer:115 student tickets and 98 general admission tickets were sold.
Explanation:
Let x represent the number of student tickets that you sold.
Let y represent the number of general admission tickets that you sold.
Total number of tickets that you sold is 213. It means that
x + y = 213
Student tickets cost $4 and general admission tickets cost $7. The total cost of all tickets that were sold is $1146. It means that
4x + 7y = 1146 - - - - - - - - - - - - 1
Substituting x = 213 - y into equation 1, it becomes
4(213 - y) + 7y = 1146
852 - 4y + 7y = 1146
- 4y + 7y = 1146 - 852
3y = 294
y = 294/3 = 98
x = 213 - y = 213 - 98
x = 115