Answer:
350 adult tickets were sold
Explanation:
Let x represent the number of adult tickets sold.
Since there were 60 fewer student tickets sold than adult tickets, the number of student tickets sold can be represented by x - 60
Create an equation that sets up these terms equal to 640, then solve for x:
(x) + (x - 60) = 640
2x - 60 = 640
2x = 700
x = 350
So, 350 adult tickets were sold