Answer:
68 adult tickets and 40 child tickets were sold.
Explanation:
Create a system of equations where a is the number of adult tickets sold and c is the number of child tickets sold:
8a + 5c = 744
a = 2c - 12
Solve by substitution by substituting the second equation into the first one:
8(2c - 12) + 5c = 744
16c - 96 + 5c = 744
21c - 96 = 744
21c = 840
c = 40
So, 40 child tickets were sold. Plug this into the second equation to solve for a:
a = 2c - 12
a = 2(40) - 12
a = 80 - 12
a = 68
So, 68 adult tickets and 40 child tickets were sold.