Answer: [tex]19x+11y \ge 4500[/tex]
=============================================
Explanation:
x = number of adults
y = number of students
The expression 19x represents the money from all the adults while 11y represents the money from all the students (since we get $19 per adult and $11 per student).
In total, the money collected is 19x+11y dollars.
We want this total to be $4500 or larger.
So that's how we get the final answer of [tex]19x+11y \ge 4500[/tex]