Let x represent the quantity of child tickets sold and y represent the quantity of adult tickets sold
Child (x): $45 each
Adult (y): $85
Cost equation: 45x + 85y = 72000
Quantity equation: x + y = 1000
45x + 85y = 72000 → 45x + 85y = 72000
-45( x + y = 1000) → -45x - 45y = -45000
40y = 27000
y = 625
Quantity equation: x + y = 1000 → x + (625) = 1000 → x = 375
Answer: 375 child tickets and 625 adult tickets
44x