Answer:
1. Sells a tract of land it has held for years - Investing Activity
2. Increases its use of trade credit from suppliers - Operating activity
3. Improves profit margin and increases net income - Operating activity
4. Issues new shares of preferred stock - Financing activity
5. Tightens its credit policy with its customers - Operating activity
6. Buys back shares of common stock - Financing activity
7. Buys new equipment and machinery - Investing Activity
8. Issues new notes payable - Financing activity