- Class Notes regarding 2 x 2 matrices and finding their determinants and inverses (Definitions of the Multiplicative Identity Matrix, Multiplicative Inverse of a Matrix, and the Determinant of a 2 x 2 Matrix.)- A worksheet of basic skill practice (With detailed answer key), including work on the following word problem: "A city has a stable group of 45,000 households. Since last year, 84% of the households that used to use carrier A remained with carrier A, while 16% switched to carrier B. 93