2. Matrix – is a rectangular arrangement of numbers in rows and columns. Dimensions – Size – m is rows, n is columns. m x n ( row ∙ column) Elements – The numbers in a matrix Equal matrices – They have the same dimensions and the elements in corresponding positions are equal. Scalar – In matrix algebra, a real number Scalar multiplication – you multiply each element in the matrix by the scalar

3. Row 1 Row 2 Row 3 Row m Column 1Column 2Column 3 Column 4

4. A matrix of m rows and n columns is called a matrix with dimensions m x n. 2 X 3 3 X 3 2 X 1 1 X 2

5. 3 X 22 X 23 X 3 1 X 22 X 11 X 1

7. To add matrices, we add the corresponding elements. They must have the same dimensions. A + B

8. To subtract matrices, we subtract the corresponding elements. The matrices must have the same dimensions.

10. Scalar Multiplication: We multiply each # inside our matrix by k.

12. Determinants

13. = ad - cb Determinant of a 2x2

14. Ex 8 Evaluate the determinant =1(7)— 2(4) = 7 - 8 = -1

15. Ex 9 Evaluate the determinant =7(3)— 2(2) = 21 - 4 = 17

16. |A| =aei+ bfg+ cdh- gec- hfa- idb The Determinant of a 3X3 Matrix

21. Scalar Multiplication:

22. 6x+8=26 6x=18 x=3 10-2y=8 -2y=-2 y=1