Answer: 72 adult tickets were sold.
Step-by-step explanation:
Let x represent the number of adult tickets that were sold.
Let y represent the number of senior tickets that were sold.
A theatre sold a total of 98 adult and senior tickets. It means that
x + y = 98
x = 98 - y - - - - - - - - - - - - -1
Adult tickets sold for 12$ each and senior tickets sold for 8$ each bringing in a total of 1,072$. This means that
12x + 8y = 1072 - - - - - - - - - - - 2
Substituting equation 1 into equation 2, it becomes
12(98 - y) + 8y = 1072
1176 - 12y + 8y = 1072
- 12y + 8y = 1072 - 1176
- 4y = - 104
y = - 104/ - 4
y = 26
Substituting y = 26 into equation 1, it becomes
x = 98 - 26 = 72