Let x represent the number of tickets that he sold at the local theatre.
From the information given, Seth earns $25 a day and $3 for each ticket he sells at the local theatre. The expression representing the amount earned from selling x tickets in a day is
25 + 3x.
To earn at least $115, it means that the amount he would earn is greater than or equal to $115. the symbol for 'greater than or equal to' is '≥'
Therefore, the inequality representing this scenario is
25 + 3x ≥ 115
To solve the inequality, we would subtract 25 from both sides of the inequality. We have
25 - 25 + 3x ≥ 115 - 25
3x ≥ 90
Dividing both sides of the inequality by 3, we have
3x/3 ≥ 90/3
x ≥ 30
He must sell at least 30 tickets to earn at least $115