Answer:250 adult tickets were sold.
Explanation:
Let x represent the number of adult tickets sold for the school play.
Let y represent the number of student tickets sold for the school play.
A total of 439 tickets were sold for the school play. This means that
x + y = 439 - - - - - - - - - - - - - - 1
There were 61 fewer students tickets sold than adults tickets. This means that
x - 61 = y
Substituting y = x - 61 into equation 1, it becomes
x + x - 61 = 439
2x - 61 = 439
2x = 439 + 61
2x = 500
x = 500/2 = 250
y = x - 61 = 250 - 61
y = 189