**Learning objectives**

- Perform basic arithmetic operations with matrices
- Invert square matrices (when possible) using row operations
- Explore criteria for invertibility

**Before class**

- Read Lay sections 2.1, 2.2, 2.3
- Consult notes to the textbook (if you wish)
- Ponder Lay problems 2.1: 5, 13, 15, 17, 18, 19, 21, 24, 27; 2.2: 1, 5, 9, 13, 15, 17, 21, 35; 2.3: 1-4, 11, 13, 17, 33.
- Post to Piazza

**In class**

- Work and discuss matrix problems