Question 13784
No, you have a simple error. If y is the number of tickets sold for couples, then 2y persons attend for those tickets. So, x + 2y = 128. Your equation for the dollar amount of x and y ticket sales is correct. 
Solve x + 2y = 128 and 20x + 35y = 2280.
[I got x=16 and y=56]