Final answer:
Seo-yeon needs to set up an inequality where x represents the additional soccer balls to purchase. The inequality 17 + x ≥ 3t reflects that after purchasing, the total soccer balls must be at least three times the number of teams. To find x, multiply the number of teams by three and subtract 17.
Step-by-step explanation:
To determine how many soccer balls Seo-yeon needs to buy for the community sports league, we must first establish an inequality that considers the current supply and the minimum requirement for each team. Given that there are already 17 soccer balls available and each team requires at least 3 soccer balls, we need to represent the situation with a variable and an inequality. Let the variable x represent the number of soccer balls Seo-yeon needs to purchase.
The inequality would be:
17 + x ≥ 3t,
where t is the number of teams in the league. This inequality states that the total number of soccer balls available after purchasing (17 plus x) must be greater than or equal to three times the number of teams (3t).
To solve for x, Seo-yeon would need to know the total number of teams and then subtract the current number of soccer balls from three times that number.