Answer:
At the carnival, 400 adult tickets were sold and 300 child tickets were sold.
Explanation:
Define Variables
- Let x be the number of adult tickets
- Let y be the number of child tickets
Create System
A total of 700 tickets were sold:

Given an adult ticket cost $10 and a child's ticket cost $5, and the total amount of tickets sold is $5,500:

Therefore, the system of equations that models the given problem is:

Solve the System
Rearrange the first equation to isolate y:

Substitute the found expression for y into the second equation to eliminate y:

Solve the equation for x:




Therefore, 400 adult tickets were sold.
Substitute the found value of x into the equation for y and solve for y:


Therefore, 300 child tickets were sold.
Check your Answer
Substitute the found values of x and y into the two equations:


Write an Answer Statement
At the carnival, 400 adult tickets were sold and 300 child tickets were sold.