Answer:
x = 638
y = 1190 - 638 = 552
Explanation:
Let x = premium seats
let y = regular seats
x + y = 1190 (ten were not sold
30x + 20y = 30180 (amount collected
now multiply the first equation by 20 and subtract
20x + 20y = 23800
30x + 20y = 30180
-10x = -6380
x = 638
y = 1190 - 638 = 552
check it by multipying x and y by their price to see if you come up with the correct amount
Hope this helps