Answer:
11 tickets
Step-by-step explanation:
1. write an equation:
First, variable x symbolizes the number of adults who bought tickets. And variable y symbolizes the number of students.
If each adult paid $6, and each student paid $4, and the total dollars you've collected is 104, this is how we'll write our equation:
6x + 4y = 104
2. we can write another equation based on this information: "You sold 21 tickets". Which concludes that the number of tickets adults and students had paid for equals the number of tickets you've sold:
x + y = 21
3. now, we've got two equations. Let's compensate:
x + y = 21
x = 21 - y
6x + 4y = 104
6 (21 - y) + 4y = 104
126 - 6y + 4y = 104
-6y + 4y = -22
-2y = -22
y = -22 / -2
y = 11
So the number of student tickets is 11.
