Final answer:
To meet their fundraising goal of at least $180, the tennis team must sell at least 80 key chains at $2.25 each.
Step-by-step explanation:
To find the number of key chains the tennis team must sell to meet their fundraising goal, we can set up an inequality equation. Let x be the number of key chains. Since each key chain is sold for $2.25, we can multiply the number of key chains by the price per key chain to find the total amount raised. The inequality is: 2.25x >= 180. To solve for x, we divide both sides of the inequality by 2.25: x >= 80.
Therefore, the tennis team must sell at least 80 key chains to meet their fundraising goal of raising at least $180.