Say the number of adult tickets is x. That means the number of student tickets is 71 less, making it x - 71.
We can add the number of student and adult tickets, because we know their sum is 479.
x + x - 71 = 479
Now, we solve for x.
2x - 71 = 479
2x = 550
x = 275
So, there were 275 adult tickets sold.